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Yang N, Liu M, Han J, Jiang M, Zeng Y, Liu Y, Xiang H, Zheng Y. Rational engineering of Halomonas salifodinae to enhance hydroxyectoine production under lower-salt conditions. Appl Microbiol Biotechnol 2024; 108:353. [PMID: 38819481 PMCID: PMC11142988 DOI: 10.1007/s00253-024-13197-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 05/01/2024] [Accepted: 05/21/2024] [Indexed: 06/01/2024]
Abstract
Hydroxyectoine is an important compatible solute that holds potential for development into a high-value chemical with broad applications. However, the traditional high-salt fermentation for hydroxyectoine production presents challenges in treating the high-salt wastewater. Here, we report the rational engineering of Halomonas salifodinae to improve the bioproduction of hydroxyectoine under lower-salt conditions. The comparative transcriptomic analysis suggested that the increased expression of ectD gene encoding ectoine hydroxylase (EctD) and the decreased expressions of genes responsible for tricarboxylic acid (TCA) cycle contributed to the increased hydroxyectoine production in H. salifodinae IM328 grown under high-salt conditions. By blocking the degradation pathway of ectoine and hydroxyectoine, enhancing the expression of ectD, and increasing the supply of 2-oxoglutarate, the engineered H. salifodinae strain HS328-YNP15 (ΔdoeA::PUP119-ectD p-gdh) produced 8.3-fold higher hydroxyectoine production than the wild-type strain and finally achieved a hydroxyectoine titer of 4.9 g/L in fed-batch fermentation without any detailed process optimization. This study shows the potential to integrate hydroxyectoine production into open unsterile fermentation process that operates under low-salinity and high-alkalinity conditions, paving the way for next-generation industrial biotechnology. KEY POINTS: • Hydroxyectoine production in H. salifodinae correlates with the salinity of medium • Transcriptomic analysis reveals the limiting factors for hydroxyectoine production • The engineered strain produced 8.3-fold more hydroxyectoine than the wild type.
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Affiliation(s)
- Niping Yang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
- School of Life Sciences, Hebei University, Baoding, 071002, China
| | - Mengshuang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jing Han
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - Mingyue Jiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yan Zeng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - Ying Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - Hua Xiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanning Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101, China.
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Ma Z, Chang R, Zhu L, Zhu D, Deng Y, Guo X, Cheng Z, Chen X. Metabolic Engineering of Corynebacterium glutamicum for Highly Efficient Production of Ectoine. ACS Synth Biol 2024. [PMID: 38607270 DOI: 10.1021/acssynbio.4c00019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Ectoine is a compatible solute that functions as a cell protector from various stresses, protecting cells and stabilizing biomolecules, and is widely used in medicine, cosmetics, and biotechnology. Microbial fermentation has been widely used for the large-scale production of ectoine, and a number of fermentation strategies have been developed to increase the ectoine yield, reduce production costs, and simplify the production process. Here, Corynebacterium glutamicum was engineered for ectoine production by heterologous expression of the ectoine biosynthesis operon ectBAC gene from Halomonas elongata, and a series of genetic modifications were implemented. This included introducing the de3 gene from Escherichia coli BL21 (DE3) to express the T7 promoter, eliminating the lysine transporter protein lysE to limit lysine production, and performing a targeted mutation lysCS301Y on aspartate kinase to alleviate feedback inhibition of lysine. The new engineered strain Ect10 obtained an ectoine titer of 115.87 g/L in an optimized fed-batch fermentation, representing the highest ectoine production level in C. glutamicum and achieving the efficient production of ectoine in a low-salt environment.
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Affiliation(s)
- Zhi Ma
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Renjie Chang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Linjiang Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Dianhao Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Yanfeng Deng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Xinying Guo
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Ziyi Cheng
- Department of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada
| | - Xiaolong Chen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
- Quzhou Eco-Industrial Innovation Institute, Zhejiang University of Technology, Quzhou 324003, PR China
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Chen J, Qiao D, Yuan T, Feng Y, Zhang P, Wang X, Zhang L. Biotechnological production of ectoine: current status and prospects. Folia Microbiol (Praha) 2024; 69:247-258. [PMID: 37962826 DOI: 10.1007/s12223-023-01105-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 11/05/2023] [Indexed: 11/15/2023]
Abstract
Ectoine is an important natural secondary metabolite in halophilic microorganisms. It protects cells against environmental stressors, such as salinity, freezing, drying, and high temperatures. Ectoine is widely used in medical, cosmetic, and other industries. Due to the commercial market demand of ectoine, halophilic microorganisms are the primary method for producing ectoine, which is produced using the industrial fermentation process "bacterial milking." The method has some limitations, such as the high salt concentration fermentation, which is highly corrosive to the equipment, and this also increases the difficulty of downstream purification and causes high production costs. The ectoine synthesis gene cluster has been successfully heterologously expressed in industrial microorganisms, and the yield of ectoine was significantly increased and the cost was reduced. This review aims to summarize and update microbial production of ectoine using different microorganisms, environments, and metabolic engineering and fermentation strategies and provides important reference for the development and application of ectoine.
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Affiliation(s)
- Jun Chen
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China
- Anhui Engineering Research Center for Eco-Agriculture of Traditional Chinese Medicine, West Anhui University, Lu'an, 23702, China
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Ministry of Natural Resources, State Oceanic Administration & Second Institute of Oceanography, Hangzhou, 310012, China
| | - Deliang Qiao
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China
- Anhui Province Key Laboratory for Quality Evaluationand, Improvement of Traditional Chinese Medicine, West Anhui University, Lu, 237012, China
| | - Tao Yuan
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China
| | - Yeyuan Feng
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China
| | - Pengjun Zhang
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China
| | - Xuejun Wang
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China
| | - Li Zhang
- College of Biotechnology and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China.
- Anhui Province Key Laboratory for Quality Evaluationand, Improvement of Traditional Chinese Medicine, West Anhui University, Lu, 237012, China.
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Yu J, Zhang Y, Liu H, Liu Y, Mohsin A, Liu Z, Zheng Y, Xing J, Han J, Zhuang Y, Guo M, Wang Z. Temporal dynamics of stress response in Halomonas elongata to NaCl shock: physiological, metabolomic, and transcriptomic insights. Microb Cell Fact 2024; 23:88. [PMID: 38519954 PMCID: PMC10960403 DOI: 10.1186/s12934-024-02358-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/06/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND The halophilic bacterium Halomonas elongata is an industrially important strain for ectoine production, with high value and intense research focus. While existing studies primarily delve into the adaptive mechanisms of this bacterium under fixed salt concentrations, there is a notable dearth of attention regarding its response to fluctuating saline environments. Consequently, the stress response of H. elongata to salt shock remains inadequately understood. RESULTS This study investigated the stress response mechanism of H. elongata when exposed to NaCl shock at short- and long-time scales. Results showed that NaCl shock induced two major stresses, namely osmotic stress and oxidative stress. In response to the former, within the cell's tolerable range (1-8% NaCl shock), H. elongata urgently balanced the surging osmotic pressure by uptaking sodium and potassium ions and augmenting intracellular amino acid pools, particularly glutamate and glutamine. However, ectoine content started to increase until 20 min post-shock, rapidly becoming the dominant osmoprotectant, and reaching the maximum productivity (1450 ± 99 mg/L/h). Transcriptomic data also confirmed the delayed response in ectoine biosynthesis, and we speculate that this might be attributed to an intracellular energy crisis caused by NaCl shock. In response to oxidative stress, transcription factor cysB was significantly upregulated, positively regulating the sulfur metabolism and cysteine biosynthesis. Furthermore, the upregulation of the crucial peroxidase gene (HELO_RS18165) and the simultaneous enhancement of peroxidase (POD) and catalase (CAT) activities collectively constitute the antioxidant defense in H. elongata following shock. When exceeding the tolerance threshold of H. elongata (1-13% NaCl shock), the sustained compromised energy status, resulting from the pronounced inhibition of the respiratory chain and ATP synthase, may be a crucial factor leading to the stagnation of both cell growth and ectoine biosynthesis. CONCLUSIONS This study conducted a comprehensive analysis of H. elongata's stress response to NaCl shock at multiple scales. It extends the understanding of stress response of halophilic bacteria to NaCl shock and provides promising theoretical insights to guide future improvements in optimizing industrial ectoine production.
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Affiliation(s)
- Junxiong Yu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Yue Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Hao Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Yuxuan Liu
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Ali Mohsin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Zebo Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Yanning Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - Jianmin Xing
- Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Jing Han
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - Yingping Zhuang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Meijin Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China.
| | - Zejian Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China.
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Hu Q, Sun S, Zhang Z, Liu W, Yi X, He H, Scrutton NS, Chen GQ. Ectoine hyperproduction by engineered Halomonas bluephagenesis. Metab Eng 2024; 82:238-249. [PMID: 38401747 DOI: 10.1016/j.ymben.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 02/19/2024] [Indexed: 02/26/2024]
Abstract
Ectoine, a crucial osmoprotectant for salt adaptation in halophiles, has gained growing interest in cosmetics and medical industries. However, its production remains challenged by stringent fermentation process in model microorganisms and low production level in its native producers. Here, we systematically engineered the native ectoine producer Halomonas bluephagenesis for ectoine production by overexpressing ectABC operon, increasing precursors availability, enhancing product transport system and optimizing its growth medium. The final engineered H. bluephagenesis produced 85 g/L ectoine in 52 h under open unsterile incubation in a 7 L bioreactor in the absence of plasmid, antibiotic or inducer. Furthermore, it was successfully demonstrated the feasibility of decoupling salt concentration with ectoine synthesis and co-production with bioplastic P(3HB-co-4HB) by the engineered H. bluephagenesis. The unsterile fermentation process and significantly increased ectoine titer indicate that H. bluephagenesis as the chassis of Next-Generation Industrial Biotechnology (NGIB), is promising for the biomanufacturing of not only intracellular bioplastic PHA but also small molecular compound such as ectoine.
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Affiliation(s)
- Qitiao Hu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China; Manchester Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, UK
| | - Simian Sun
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhongnan Zhang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wei Liu
- PhaBuilder Biotechnology Co. Ltd., Shunyi District, Beijing 101309, China
| | - Xueqing Yi
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Hongtao He
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, UK
| | - Guo-Qiang Chen
- School of Life Sciences, Tsinghua University, Beijing, 100084, China; Manchester Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, UK; Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China.
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Cheng L, Zhang Z, Zhu D, Luo Q, Lu X. Glucosylglycerol phosphorylase, a potential novel pathway of microbial glucosylglycerol catabolism. Appl Microbiol Biotechnol 2024; 108:214. [PMID: 38363425 PMCID: PMC10873239 DOI: 10.1007/s00253-024-13035-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/11/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024]
Abstract
Glucosylglycerol (GG) is a natural compatible solute that can be synthesized by many cyanobacteria and a few heterotrophic bacteria under high salinity conditions. In cyanobacteria, GG is synthesized by GG-phosphate synthase and GG-phosphate phosphatase, and a hydrolase GGHA catalyzes its degradation. In heterotrophic bacteria (such as some Marinobacter species), a fused form of GG-phosphate phosphatase and GG-phosphate synthase is present, but the cyanobacteria-like degradation pathway is not available. Instead, a phosphorylase GGP, of which the coding gene is located adjacent to the gene that encodes the GG-synthesizing enzyme, is supposed to perform the GG degradation function. In the present study, a GGP homolog from the salt-tolerant M. salinexigens ZYF650T was characterized. The recombinant GGP catalyzed GG decomposition via a two-step process of phosphorolysis and hydrolysis in vitro and exhibited high substrate specificity toward GG. The activity of GGP was enhanced by inorganic salts at low concentrations but significantly inhibited by increasing salt concentrations. While the investigation on the physiological role of GGP in M. salinexigens ZYF650T was limited due to the failed induction of GG production, the heterologous expression of ggp in the living cells of the GG-producing cyanobacterium Synechocystis sp. PCC 6803 significantly reduced the salt-induced GG accumulation. Together, these data suggested that GGP may represent a novel pathway of microbial GG catabolism. KEY POINTS: • GGP catalyzes GG degradation by a process of phosphorolysis and hydrolysis • GGP-catalyzed GG degradation is different from GGHA-based GG degradation • GGP represents a potential novel pathway of microbial GG catabolism.
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Affiliation(s)
- Lin Cheng
- College of Chemical Engineering and Materials Sciences, Tianjin University of Science & Technology, Tianjin, 300457, China
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Rd 189, Qingdao, 266101, China
| | - Zhichao Zhang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Rd 189, Qingdao, 266101, China
- Shandong Energy Institute, Songling Rd 189, Qingdao, 266101, China
- Qingdao New Energy Shandong Laboratory, Songling Rd 189, Qingdao, 266101, China
| | - Daling Zhu
- College of Chemical Engineering and Materials Sciences, Tianjin University of Science & Technology, Tianjin, 300457, China.
| | - Quan Luo
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Rd 189, Qingdao, 266101, China.
- Shandong Energy Institute, Songling Rd 189, Qingdao, 266101, China.
- Qingdao New Energy Shandong Laboratory, Songling Rd 189, Qingdao, 266101, China.
| | - Xuefeng Lu
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Rd 189, Qingdao, 266101, China
- Shandong Energy Institute, Songling Rd 189, Qingdao, 266101, China
- Qingdao New Energy Shandong Laboratory, Songling Rd 189, Qingdao, 266101, China
- Marine Biology and Biotechnology Laboratory, Qingdao National Laboratory for Marine Science and Technology, Wenhai Rd 168, Qingdao, 266237, China
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Orhan F, Demirci A, Efe D, Aydın R, Bozarı S. Usage of ectoine as a cryoprotectant for cryopreservation of lactic acid bacteria. Folia Microbiol (Praha) 2024; 69:133-144. [PMID: 37917277 DOI: 10.1007/s12223-023-01098-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 09/29/2023] [Indexed: 11/04/2023]
Abstract
Streptococcus thermophilus, the only Streptococcus species considered "Generally Recognized Safe", has been used widely in the food industry. This bacterium is one of the most valuable industrial lactic acid bacterial species. Due to the importance of this bacterium in industrial applications, it should be stored for a long time without losing its metabolic properties. The present study aimed to investigate the cryoprotectant effect of three compatible solutes (ectoine, trehalose, and sucrose) on bacterial cells stored at different temperatures (frozen at -80 °C or freeze-dried and subsequently stored at +4, -20, and -80 °C) for three months. The bacterial cells were tested for cell viability, bile salt tolerance, and lactic acid production before and after processing. The highest cell viability, bile salt tolerance, and lactic acid production were obtained with ectoine and under frozen (storage at -80 °C) conditions. In freeze-dried and subsequently stored at various temperatures, the best preservation was obtained at -80 °C, followed by -20 °C and +4 °C. Moreover, when ectoine's preservation potential was compared to other cryoprotectants, ectoine showed the highest preservation, followed by trehalose and sucrose. Although ectoine has a variety of qualities that have been proven, in the current work, we have shown for the first time that ectoine has cryoprotectant potential in yogurt starter cultures (S. thermophilus).
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Affiliation(s)
- Furkan Orhan
- Art and Science Faculty, Department of Molecular Biology and Genetics, Agri Ibrahim Cecen University, Agri, 4100, Türkiye.
- Central Research and Application Laboratory, Agri Ibrahim Cecen University, Agri, 4100, Türkiye.
| | - Abdullah Demirci
- Central Research and Application Laboratory, Agri Ibrahim Cecen University, Agri, 4100, Türkiye
| | - Derya Efe
- Department of Medicinal and Aromatic Plants, Giresun University, Giresun, Türkiye
| | - Rukiye Aydın
- Engineering Faculty, Basic Sciences Department, Samsun University, Samsun, 55420, Türkiye
| | - Sedat Bozarı
- Department of Molecular Biology and Genetics, Mus Alparslan University, Mus, 49250, Türkiye
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Zou Z, Kaothien-Nakayama P, Ogawa-Iwamura J, Nakayama H. Metabolic engineering of high-salinity-induced biosynthesis of γ-aminobutyric acid improves salt-stress tolerance in a glutamic acid-overproducing mutant of an ectoine-deficient Halomonas elongata. Appl Environ Microbiol 2024; 90:e0190523. [PMID: 38112419 PMCID: PMC10807429 DOI: 10.1128/aem.01905-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 11/08/2023] [Indexed: 12/21/2023] Open
Abstract
A moderately halophilic eubacterium, Halomonas elongata, has been used as cell factory to produce fine chemical 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine), which functions as a major osmolyte protecting the cells from high-salinity stress. To explore the possibility of using H. elongata to biosynthesize other valuable osmolytes, an ectoine-deficient salt-sensitive H. elongata deletion mutant strain KA1 (ΔectABC), which only grows well in minimal medium containing up to 3% NaCl, was subjected to an adaptive mutagenesis screening in search of mutants with restored salt tolerance. Consequently, we obtained a mutant, which tolerates 6% NaCl in minimal medium by overproducing L-glutamic acid (Glu). However, this Glu-overproducing (GOP) strain has a lower tolerance level than the wild-type H. elongata, possibly because the acidity of Glu interferes with the pH homeostasis of the cell and hinders its own cellular accumulation. Enzymatic decarboxylation of Glu to γ-aminobutyric acid (GABA) by a Glu decarboxylase (GAD) could restore cellular pH homeostasis; therefore, we introduced an engineered salt-inducible HopgadBmut gene, which encodes a wide pH-range GAD mutant, into the genome of the H. elongata GOP strain. We found that the resulting H. elongata GOP-Gad strain exhibits higher salt tolerance than the GOP strain by accumulating high concentration of GABA as an osmolyte in the cell (176.94 µmol/g cell dry weight in minimal medium containing 7% NaCl). With H. elongata OUT30018 genetic background, H. elongata GOP-Gad strain can utilize biomass-derived carbon and nitrogen compounds as its sole carbon and nitrogen sources, making it a good candidate for the development of GABA-producing cell factories.IMPORTANCEWhile the wild-type moderately halophilic H. elongata can synthesize ectoine as a high-value osmolyte via the aspartic acid metabolic pathway, a mutant H. elongata GOP strain identified in this work opens doors for the biosynthesis of alternative valuable osmolytes via glutamic acid metabolic pathway. Further metabolic engineering to install a GAD system into the H. elongata GOP strain successfully created a H. elongata GOP-Gad strain, which acquired higher tolerance to salt stress by accumulating GABA as a major osmolyte. With the ability to assimilate biomass-derived carbon and nitrogen sources and thrive in high-salinity environment, the H. elongata GOP-Gad strain can be used in the development of sustainable GABA-producing cell factories.
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Affiliation(s)
- Ziyan Zou
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Pulla Kaothien-Nakayama
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Junpei Ogawa-Iwamura
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Hideki Nakayama
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
- Institute of Integrated Science and Technology, Nagasaki University, Nagasaki, Japan
- Organization for Marine Science and Technology, Nagasaki University, Nagasaki, Japan
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9
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Feng Y, Qiu M, Shao L, Jiang Y, Zhang W, Jiang W, Xin F, Jiang M. Strategies for the biological production of ectoine by using different chassis strains. Biotechnol Adv 2024; 70:108306. [PMID: 38157997 DOI: 10.1016/j.biotechadv.2023.108306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/27/2023] [Accepted: 12/23/2023] [Indexed: 01/03/2024]
Abstract
As an amino acid derivative and a typical compatible solute, ectoine can assist microorganisms in resisting high osmotic pressure. Own to its long-term moisturizing effects, ectoine shows extensive applications in cosmetics, medicine and other fields. With the rapid development of synthetic biology and fermentation engineering, many biological strategies have been developed to improve the ectoine production and simplify the production process. Currently, the microbial fermentation has been widely used for large scaling ectoine production. Accordingly, this review will introduce the metabolic pathway for ectoine synthesis and also comprehensively evaluate both wild-type and genetically modified strains for ectoine production. Furthermore, process parameters affecting the ectoine production efficiency and adoption of low cost substrates will be evaluated. Lastly, future prospects on the improvement of ectoine production will be proposed.
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Affiliation(s)
- Yifan Feng
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Min Qiu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Lei Shao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Wankui Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
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Sengupta A, Das K, Jha N, Akhter Y, Kumar A. Molecular evolution steered structural adaptations in the DNA polymerase III α subunit of halophilic bacterium Salinibacter ruber. Extremophiles 2023; 27:20. [PMID: 37481762 DOI: 10.1007/s00792-023-01306-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/14/2023] [Indexed: 07/25/2023]
Abstract
A significant portion of the earth has a salty environment, and the literature on bacterial survival mechanisms in salty environments is limited. During molecular evolution, halophiles increase acidic amino acid residues on their protein surfaces which leads to a negatively charged surface potential that helps them to maintain the protein integrity and protect them from denaturation by competing with salt ions. Through protein family analysis, we have investigated the molecular-level adaptive features of DNA polymerase III's catalytic subunit (alpha) and its structure-function relationship. This study throws light on the novel understanding of halophilic bacterial replication and the molecular basis of salt adaptation. Comparisons of the amino acid contents and electronegativity of halophilic and mesophilic bacterial proteins revealed adaptations that allow halophilic bacteria to thrive in high salt concentrations. A significantly lower isoelectric point of halophilic bacterial proteins indicates the acidic nature. Also, an abundance of disordered regions in halophiles suggests the requirement of the salt ions that play a crucial role in their stable protein folding. Despite having similar topology, mesophilic and halophilic proteins, a set of very prominent molecular modifications was observed in the alpha subunit of halophiles.
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Affiliation(s)
- Aveepsa Sengupta
- Department of Microbiology, Tripura University (A Central University), Suryamaninagar, Agartala, Tripura, India
| | - Kunwali Das
- Department of Microbiology, Tripura University (A Central University), Suryamaninagar, Agartala, Tripura, India
| | - Nidhi Jha
- Department of Microbiology, Tripura University (A Central University), Suryamaninagar, Agartala, Tripura, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226025, India.
| | - Ashutosh Kumar
- Department of Microbiology, Tripura University (A Central University), Suryamaninagar, Agartala, Tripura, India.
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11
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Shu Z, Zhang X, Wang R, Xing J, Li Y, Zhu D, Shen G. Metabolic engineering of Halomonas campaniensis strain XH26 to remove competing pathways to enhance ectoine production. Sci Rep 2023; 13:9732. [PMID: 37322079 PMCID: PMC10272175 DOI: 10.1038/s41598-023-36975-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/13/2023] [Indexed: 06/17/2023] Open
Abstract
Ectoine has gained considerable attention as a high-value chemical with significant application potential and market demand. This study aimed to increase ectoine yields by blocking the metabolic shunt pathway of L-aspartate-4-semialdehyde, the precursor substrate in ectoine synthesis. The homoserine dehydrogenase encoded by hom in H. campaniensis strain XH26 is responsible for the metabolic shunt of L-aspartate-4-semialdehyde to glycine. CRISPR/Cas9 technology was used to seamlessly knockout hom, blocking the metabolic shunt pathway to increase ectoine yields. The ectoine yield of XH26/Δhom was 351.13 mg (g CDW)-1 after 48 h of incubation in 500 mL shake flasks using optimal medium with 1.5 mol L-1 NaCl, which was significantly higher than the 239.18 mg (g CDW)-1 of the wild-type strain. Additionally, the absence of the ectoine metabolic shunt pathway affects betaine synthesis, and thus the betaine yields of XH26/Δhom was 19.98 mg (g CDW)-1, considerably lower than the 69.58 mg (g CDW)-1 of the wild-type strain. Batch fermentation parameters were optimized, and the wild-type strain and XH26/Δhom were fermented in 3 L fermenters, resulting in a high ectoine yield of 587.09 mg (g CDW)-1 for the defective strain, which was significantly greater than the ectoine yield of 385.03 mg (g CDW)-1 of the wild-type strain. This study showed that blocking the metabolic shunt of synthetic substrates effectively increases ectoine production, and a reduction in the competitively compatible solute betaine appears to promote increased ectoine synthesis.
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Affiliation(s)
- Zhiwan Shu
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China
| | - Xin Zhang
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China
| | - Rong Wang
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China
| | - Jiangwa Xing
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China
| | - Yongzhen Li
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China
| | - Derui Zhu
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China
| | - Guoping Shen
- Research Center of Basic Medical Science, Medical College of Qinghai University, Xining, 810016, China.
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12
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Leandro T, Oliveira MC, da Fonseca MMR, Cesário MT. Co-Production of Poly(3-hydroxybutyrate) and Gluconic Acid from Glucose by Halomonas elongata. Bioengineering (Basel) 2023; 10:643. [PMID: 37370574 DOI: 10.3390/bioengineering10060643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 06/29/2023] Open
Abstract
Polyhydroxyalkanoates (PHA) are biopolyesters regarded as an attractive alternative to petroleum-derived plastics. Nitrogen limitation and phosphate limitation in glucose cultivations were evaluated for poly(3-hydroxybutyrate) (P(3HB)) production by Halomonas elongata 1H9T, a moderate halophilic strain. Co-production of P(3HB) and gluconic acid was observed in fed-batch glucose cultivations under nitrogen limiting conditions. A maximum P(3HB) accumulation of 53.0% (w/w) and a maximum co-production of 133 g/L of gluconic acid were attained. Fed-batch glucose cultivation under phosphate limiting conditions resulted in a P(3HB) accumulation of only 33.3% (w/w) and no gluconic acid production. As gluconic acid is a valuable organic acid with extensive applications in several industries, this work presents an interesting approach for the future development of an industrial process aiming at the co-production of an intracellular biopolymer, P(3HB), and a value-added extracellular product, gluconic acid.
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Affiliation(s)
- Tânia Leandro
- IBB-Institute for Bioengineering and Biosciences, Bioengineering Department, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - M Conceição Oliveira
- Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - M Manuela R da Fonseca
- IBB-Institute for Bioengineering and Biosciences, Bioengineering Department, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - M Teresa Cesário
- IBB-Institute for Bioengineering and Biosciences, Bioengineering Department, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
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13
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Nofiani R, Ardiningsih P, Zahra STA, Sukito A, Weisberg AJ, Chang JH, Mahmud T. Genome features and secondary metabolite potential of the marine symbiont Streptomyces sp. RS2. Arch Microbiol 2023; 205:244. [PMID: 37209150 DOI: 10.1007/s00203-023-03556-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 05/22/2023]
Abstract
Streptomyces sp. RS2 was isolated from an unidentified sponge collected around Randayan Island, Indonesia. The genome of Streptomyces sp. RS2 consists of a linear chromosome of 9,391,717 base pairs with 71.9% of G + C content, 8270 protein-coding genes, as well as 18 rRNA and 85 tRNA loci. Twenty-eight putative secondary metabolites biosynthetic gene clusters (BGCs) were identified in the genome sequence. Nine of them have 100% similarity to BGCs for albaflavenone, α-lipomycin, coelibactin, coelichelin, ectoine, geosmin, germicidin, hopene, and lanthionine (SapB). The remaining 19 BGCs have low (< 50%) or moderate (50-80%) similarity to other known secondary metabolite BGCs. Biological activity assays of extracts from 21 different cultures of the RS2 strain showed that SCB ASW was the best medium for the production of antimicrobial and cytotoxic compounds. Streptomyces sp. RS2 has great potential to be a producer of novel secondary metabolites, particularly those with antimicrobial and antitumor activities.
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Affiliation(s)
- Risa Nofiani
- Department of Chemistry, Universitas Tanjungpura, Pontianak, 78124, Indonesia.
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR, 97331, USA.
| | - Puji Ardiningsih
- Department of Chemistry, Universitas Tanjungpura, Pontianak, 78124, Indonesia
| | | | - Agus Sukito
- Research Center for Applied Microbiology, National Research and Innovation Agency, Bogor, 16458, Indonesia
| | - Alexandra J Weisberg
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Jeff H Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Taifo Mahmud
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR, 97331, USA
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Ballesteros-Gutiérrez M, Albareda M, Barbas C, López-Gonzálvez Á, Dunn MF, Palacios JM. A host-specific diaminobutyrate aminotransferase contributes to symbiotic performance, homoserine metabolism, and competitiveness in the Rhizobium leguminosarum/ Pisum sativum system. Front Microbiol 2023; 14:1182563. [PMID: 37260681 PMCID: PMC10228743 DOI: 10.3389/fmicb.2023.1182563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 04/25/2023] [Indexed: 06/02/2023] Open
Abstract
Rhizobium leguminosarum bv. viciae (Rlv) UPM791 effectively nodulates pea and lentil, but bacteroids contain a number of proteins differentially expressed depending on the host. One of these host-dependent proteins (C189) is similar to a diaminobutyrate-2-oxoglutarate aminotransferase (DABA-AT). DABA-AT activity was demonstrated with cell extracts and with purified protein, so C189 was renamed as Dat. The dat gene was strongly induced in the central, active area of pea nodules, but not in lentil. Mutants defective in dat were impaired in symbiotic performance with pea plants, exhibiting reduced shoot dry weight, smaller nodules, and a lower competitiveness for nodulation. In contrast, there were no significant differences between mutant and wild-type in symbiosis with lentil plants. A comparative metabolomic approach using cell-free extracts from bacteroids induced in pea and lentil showed significant differences among the strains in pea bacteroids whereas no significant differences were found in lentil. Targeted metabolomic analysis revealed that the dat mutation abolished the presence of 2,4-diaminobutyrate (DABA) in pea nodules, indicating that DABA-AT reaction is oriented toward the production of DABA from L-aspartate semialdehyde. This analysis also showed the presence of L-homoserine, a likely source of aspartate semialdehyde, in pea bacteroids but not in those induced in lentil. The dat mutant showed impaired growth when cells were grown with L-homoserine as nitrogen source. Inclusion of DABA or L-homoserine as N source suppressed pantothenate auxotropy in Rlv UPM791, suggesting DABA as source of the pantothenate precursor β-alanine. These data indicate that Rlv UPM791 Dat enzyme is part of an adaptation mechanism of this bacterium to a homoserine-rich environment such as pea nodule and rhizosphere.
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Affiliation(s)
- Marta Ballesteros-Gutiérrez
- Centro de Biotecnología y Genómica de Plantas (CBGP, UPM-INIA/CSIC), Consejo Superior de Investigaciones Científicas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Spain
| | - Marta Albareda
- Centro de Biotecnología y Genómica de Plantas (CBGP, UPM-INIA/CSIC), Consejo Superior de Investigaciones Científicas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Coral Barbas
- Facultad de Farmacia, Center for Metabolomics and Bioanalysis (CEMBIO), Universidad San Pablo-CEU, Boadilla del Monte, Spain
| | - Ángeles López-Gonzálvez
- Facultad de Farmacia, Center for Metabolomics and Bioanalysis (CEMBIO), Universidad San Pablo-CEU, Boadilla del Monte, Spain
| | - Michael F. Dunn
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas-Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - José M. Palacios
- Centro de Biotecnología y Genómica de Plantas (CBGP, UPM-INIA/CSIC), Consejo Superior de Investigaciones Científicas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
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15
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Galisteo C, de la Haba RR, Sánchez-Porro C, Ventosa A. A step into the rare biosphere: genomic features of the new genus Terrihalobacillus and the new species Aquibacillus salsiterrae from hypersaline soils. Front Microbiol 2023; 14:1192059. [PMID: 37228371 PMCID: PMC10203224 DOI: 10.3389/fmicb.2023.1192059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 04/12/2023] [Indexed: 05/27/2023] Open
Abstract
Hypersaline soils are a source of prokaryotic diversity that has been overlooked until very recently. The phylum Bacillota, which includes the genus Aquibacillus, is one of the 26 phyla that inhabit the heavy metal contaminated soils of the Odiel Saltmarshers Natural Area (Southwest Spain), according to previous research. In this study, we isolated a total of 32 strains closely related to the genus Aquibacillus by the traditional dilution-plating technique. Phylogenetic studies clustered them into two groups, and comparative genomic analyses revealed that one of them represents a new species within the genus Aquibacillus, whereas the other cluster constitutes a novel genus of the family Bacillaceae. We propose the designations Aquibacillus salsiterrae sp. nov. and Terrihalobacillus insolitus gen. nov., sp. nov., respectively, for these two new taxa. Genome mining analysis revealed dissimilitude in the metabolic traits of the isolates and their closest related genera, remarkably the distinctive presence of the well-conserved pathway for the biosynthesis of molybdenum cofactor in the species of the genera Aquibacillus and Terrihalobacillus, along with genes that encode molybdoenzymes and molybdate transporters, scarcely found in metagenomic dataset from this area. In-silico studies of the osmoregulatory strategy revealed a salt-out mechanism in the new species, which harbor the genes for biosynthesis and transport of the compatible solutes ectoine and glycine betaine. Comparative genomics showed genes related to heavy metal resistance, which seem required due to the contamination in the sampling area. The low values in the genome recruitment analysis indicate that the new species of the two genera, Terrihalobacillus and Aquibacillus, belong to the rare biosphere of representative hypersaline environments.
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16
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Li J, Xiao X, Zhou M, Zhang Y. Strategy for the Adaptation to Stressful Conditions of the Novel Isolated Conditional Piezophilic Strain Halomonas titanicae ANRCS81. Appl Environ Microbiol 2023; 89:e0130422. [PMID: 36912687 PMCID: PMC10057041 DOI: 10.1128/aem.01304-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 02/10/2023] [Indexed: 03/14/2023] Open
Abstract
Microorganisms have successfully predominated deep-sea ecosystems, while we know little about their adaptation strategy to multiple environmental stresses therein, including high hydrostatic pressure (HHP). Here, we focused on the genus Halomonas, one of the most widely distributed halophilic bacterial genera in marine ecosystems and isolated a piezophilic strain Halomonas titanicae ANRCS81 from Antarctic deep-sea sediment. The strain grew under a broad range of temperatures (2 to 45°C), pressures (0.1 to 55 MPa), salinities (NaCl, 0.5 to 17.5%, wt/vol), and chaotropic agent (Mg2+, 0 to 0.9 M) with either oxygen or nitrate as an electron acceptor. Genome annotation revealed that strain ANRCS81 expressed potential antioxidant genes/proteins and possessed versatile energy generation pathways. Based on the transcriptomic analysis, when the strain was incubated at 40 MPa, genes related to antioxidant defenses, anaerobic respiration, and fermentation were upregulated, indicating that HHP induced intracellular oxidative stress. Under HHP, superoxide dismutase (SOD) activity increased, glucose consumption increased with less CO2 generation, and nitrate/nitrite consumption increased with more ammonium generation. The cellular response to HHP represents the common adaptation developed by Halomonas to inhabit and drive geochemical cycling in deep-sea environments. IMPORTANCE Microbial growth and metabolic responses to environmental changes are core aspects of adaptation strategies developed during evolution. In particular, high hydrostatic pressure (HHP) is the most common but least examined environmental factor driving microbial adaptation in the deep sea. According to recent studies, microorganisms developed a common adaptation strategy to multiple stresses, including HHP, with antioxidant defenses and energy regulation as key components, but experimental data are lacking. Meanwhile, cellular SOD activity is elevated under HHP. The significance of this research lies in identifying the HHP adaptation strategy of a Halomonas strain at the genomic, transcriptomic, and metabolic activity levels, which will allow researchers to bridge environmental factors with the ecological function of marine microorganisms.
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Affiliation(s)
- Jiakang Li
- Shanghai Key Laboratory of Polar Life and Environment Sciences, School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Xiang Xiao
- Shanghai Key Laboratory of Polar Life and Environment Sciences, School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
| | - Meng Zhou
- Shanghai Key Laboratory of Polar Life and Environment Sciences, School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Yu Zhang
- Shanghai Key Laboratory of Polar Life and Environment Sciences, School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
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17
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Dong Z, Sun T, Zhang W, Chen L. Improved salt tolerance of Synechococcus elongatus PCC 7942 by heterologous synthesis of compatible solute ectoine. Front Microbiol 2023; 14:1123081. [PMID: 36819058 PMCID: PMC9932913 DOI: 10.3389/fmicb.2023.1123081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Salt stress is one of the essential abiotic stresses for the survival of cyanobacteria. However, the realization of large-scale cultivation of cyanobacteria is inseparable from the utilization of abundant seawater resources. Therefore, research on the regulatory mechanism, as well as the improvement of salt tolerance of cyanobacteria is fundamental. Ectoine, a compatible solute which was found in halophilic microorganisms, has potentiality to confer salt tolerance. Here in this article, the salt tolerance of Synechococcus elongatus PCC 7942 (Syn7942) was significantly improved via expressing the ectoine biosynthetic pathway, reaching an increased final OD750 by 20% under 300 mM NaCl and 80% under 400 mM NaCl than that of wild-type (WT), respectively. Encouragingly, the engineered strain could even survive under 500 mM NaCl which was lethal to WT. In addition, by introducing the ectoine synthetic pathway into the sucrose-deficient strain, the salt tolerance of the obtained strain Syn7942/Δsps-ect was restored to the level of WT under 300 mM NaCl stress, demonstrating that ectoine could substitute for sucrose to combat against salt stress in Syn7942. In order to study the difference in the regulation of mechanism on the salt adaptation process after replacing sucrose with ectoine, transcriptomic analysis was performed for Syn7942/Δsps-ect and WT. The differentially expressed gene analysis successfully identified 19 up-regulated genes and 39 down-regulated genes in Syn7942/Δsps-ect compared with WT under salt stress condition. The results also showed that the global regulation of Syn7942/Δsps-ect and WT had certain differences in the process of salt adaptation, in which Syn7942/Δsps-ect reduced the demand for the intensity of sulfur metabolism in this process. This study provides a valuable reference for further salt tolerance engineering in cyanobacteria.
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Affiliation(s)
- Zhengxin Dong
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, China,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China,*Correspondence: Tao Sun,
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, China,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, China,Lei Chen,
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18
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Production and Recovery of Ectoine: A Review of Current State and Future Prospects. Processes (Basel) 2023. [DOI: 10.3390/pr11020339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) is a revolutionizing substance with vast applications in the cosmetic and food industries. Ectoine is often sourced from halobacteria. The increasing market demand for ectoine has urged the development of cost-effective and sustainable large-scale production of ectoine from microbial sources. This review describes the existing and potential microbial sources of ectoine and its derivatives, as well as microbial production and fermentation approaches for ectoine recovery. In addition, conventional methods and emerging technologies for enhanced production and recovery of ectoine from microbial fermentation with a focus on the aqueous biphasic system (ABS) are discussed. The ABS is a practically feasible approach for the integration of fermentation, cell disruption, bioconversion, and clarification of various biomolecules in a single-step operation. Nonetheless, the implementation of the ABS on an industrial-scale basis for the enhanced production and recovery of ectoine is yet to be exploited. Therefore, the feasibility of the ABS to integrate the production and direct recovery of ectoine from microbial sources is also highlighted in this review.
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Girard L, Lood C, De Mot R, van Noort V, Baudart J. Genomic diversity and metabolic potential of marine Pseudomonadaceae. Front Microbiol 2023; 14:1071039. [PMID: 37168120 PMCID: PMC10165715 DOI: 10.3389/fmicb.2023.1071039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 02/21/2023] [Indexed: 05/13/2023] Open
Abstract
Recent changes in the taxonomy of the Pseudomonadaceae family have led to the delineation of three new genera (Atopomonas, Halopseudomonas and Stutzerimonas). However, the genus Pseudomonas remains the most densely populated and displays a broad genetic diversity. Pseudomonas are able to produce a wide variety of secondary metabolites which drives important ecological functions and have a great impact in sustaining their lifestyles. While soilborne Pseudomonas are constantly examined, we currently lack studies aiming to explore the genetic diversity and metabolic potential of marine Pseudomonas spp. In this study, 23 Pseudomonas strains were co-isolated with Vibrio strains from three marine microalgal cultures and rpoD-based phylogeny allowed their assignment to the Pseudomonas oleovorans group (Pseudomonas chengduensis, Pseudomonas toyotomiensis and one new species). We combined whole genome sequencing on three selected strains with an inventory of marine Pseudomonas genomes to assess their phylogenetic assignations and explore their metabolic potential. Our results revealed that most strains are incorrectly assigned at the species level and half of them do not belong to the genus Pseudomonas but instead to the genera Halopseudomonas or Stutzerimonas. We highlight the presence of 26 new species (Halopseudomonas (n = 5), Stutzerimonas (n = 7) and Pseudomonas (n = 14)) and describe one new species, Pseudomonas chaetocerotis sp. nov. (type strain 536T = LMG 31766T = DSM 111343T). We used genome mining to identify numerous BGCs coding for the production of diverse known metabolites (i.e., osmoprotectants, photoprotectants, quorum sensing molecules, siderophores, cyclic lipopeptides) but also unknown metabolites (e.g., ARE, hybrid ARE-DAR, siderophores, orphan NRPS gene clusters) awaiting chemical characterization. Finally, this study underlines that marine environments host a huge diversity of Pseudomonadaceae that can drive the discovery of new secondary metabolites.
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Affiliation(s)
- Léa Girard
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Léa Girard,
| | - Cédric Lood
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Department of Biosystems, Laboratory of Gene Technology, KU Leuven, Leuven, Belgium
| | - René De Mot
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Vera van Noort
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Institute of Biology, Leiden University, Leiden, Netherlands
| | - Julia Baudart
- Laboratoire de Biodiversité et Biotechnologie Microbiennes, Sorbonne Université, CNRS, Observatoire Océanologique, Banyuls-sur-Mer, France
- *Correspondence: Julia Baudart,
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20
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Jungmann L, Hoffmann SL, Lang C, De Agazio R, Becker J, Kohlstedt M, Wittmann C. High-efficiency production of 5-hydroxyectoine using metabolically engineered Corynebacterium glutamicum. Microb Cell Fact 2022; 21:274. [PMID: 36578077 PMCID: PMC9798599 DOI: 10.1186/s12934-022-02003-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/17/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Extremolytes enable microbes to withstand even the most extreme conditions in nature. Due to their unique protective properties, the small organic molecules, more and more, become high-value active ingredients for the cosmetics and the pharmaceutical industries. While ectoine, the industrial extremolyte flagship, has been successfully commercialized before, an economically viable route to its highly interesting derivative 5-hydroxyectoine (hydroxyectoine) is not existing. RESULTS Here, we demonstrate high-level hydroxyectoine production, using metabolically engineered strains of C. glutamicum that express a codon-optimized, heterologous ectD gene, encoding for ectoine hydroxylase, to convert supplemented ectoine in the presence of sucrose as growth substrate into the desired derivative. Fourteen out of sixteen codon-optimized ectD variants from phylogenetically diverse bacterial and archaeal donors enabled hydroxyectoine production, showing the strategy to work almost regardless of the origin of the gene. The genes from Pseudomonas stutzeri (PST) and Mycobacterium smegmatis (MSM) worked best and enabled hydroxyectoine production up to 97% yield. Metabolic analyses revealed high enrichment of the ectoines inside the cells, which, inter alia, reduced the synthesis of other compatible solutes, including proline and trehalose. After further optimization, C. glutamicum Ptuf ectDPST achieved a titre of 74 g L-1 hydroxyectoine at 70% selectivity within 12 h, using a simple batch process. In a two-step procedure, hydroxyectoine production from ectoine, previously synthesized fermentatively with C. glutamicum ectABCopt, was successfully achieved without intermediate purification. CONCLUSIONS C. glutamicum is a well-known and industrially proven host, allowing the synthesis of commercial products with granted GRAS status, a great benefit for a safe production of hydroxyectoine as active ingredient for cosmetic and pharmaceutical applications. Because ectoine is already available at commercial scale, its use as precursor appears straightforward. In the future, two-step processes might provide hydroxyectoine de novo from sugar.
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Affiliation(s)
- Lukas Jungmann
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Sarah Lisa Hoffmann
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Caroline Lang
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Raphaela De Agazio
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Judith Becker
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Michael Kohlstedt
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Christoph Wittmann
- grid.11749.3a0000 0001 2167 7588Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
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21
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Ma Z, Wu C, Zhu L, Chang R, Ma W, Deng Y, Chen X. Bioactivity profiling of the extremolyte ectoine as a promising protectant and its heterologous production. 3 Biotech 2022; 12:331. [PMID: 36311375 PMCID: PMC9606177 DOI: 10.1007/s13205-022-03370-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 09/20/2022] [Indexed: 11/28/2022] Open
Abstract
Ectoine is a compatible solutes that is diffusely dispersed in bacteria and archaea. It plays a significant role as protectant against various external pressures, such as high temperature, high osmolarity, dryness and radiation, in cells. Ectoine can be utilized in cosmetics due to its properties of moisturizing and antiultraviolet. It can also be used in the pharmaceutical industry for treating various diseases. Therefore, strong protection of ectoine creates a high commercial value. Its current market value is approximately US$1000 kg-1. However, traditional ectoine production in high-salinity media causes high costs of equipment loss and wastewater treatment. There is a growing attention to reduce the salinity of the fermentation broth without sacrificing the production of ectoine. Thus, heterologous production of ectoine in nonhalophilic microorganisms may represent the new generation of the industrial production of ectoine. In this review, we summarized and discussed the biological activities of ectoine on cell and human health protection and its heterologous production.
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Affiliation(s)
- Zhi Ma
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Chutian Wu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Linjiang Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Renjie Chang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Weilin Ma
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Yanfeng Deng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Xiaolong Chen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
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22
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Cho S, Lee YS, Chai H, Lim SE, Na JG, Lee J. Enhanced production of ectoine from methane using metabolically engineered Methylomicrobium alcaliphilum 20Z. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:5. [PMID: 35418141 PMCID: PMC8759281 DOI: 10.1186/s13068-022-02104-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 01/04/2022] [Indexed: 11/22/2022]
Abstract
Background Ectoine (1,3,4,5-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) is an attractive compatible solute because of its wide industrial applications. Previous studies on the microbial production of ectoine have focused on sugar fermentation. Alternatively, methane can be used as an inexpensive and abundant resource for ectoine production by using the halophilic methanotroph, Methylomicrobium alcaliphilum 20Z. However, there are some limitations, including the low production of ectoine from methane and the limited tools for the genetic manipulation of methanotrophs to facilitate their use as industrial strains. Results We constructed M. alcaliphilum 20ZDP with a high conjugation efficiency and stability of the episomal plasmid by the removal of its native plasmid. To improve the ectoine production in M. alcaliphilum 20Z from methane, the ectD (encoding ectoine hydroxylase) and ectR (transcription repressor of the ectABC-ask operon) were deleted to reduce the formation of by-products (such as hydroxyectoine) and induce ectoine production. When the double mutant was batch cultured with methane, ectoine production was enhanced 1.6-fold compared to that obtained with M. alcaliphilum 20ZDP (45.58 mg/L vs. 27.26 mg/L) without growth inhibition. Notably, a maximum titer of 142.32 mg/L was reached by the use of an optimized medium for ectoine production containing 6% NaCl and 0.05 μM of tungsten without hydroxyectoine production. This result demonstrates the highest ectoine production from methane to date. Conclusions Ectoine production was significantly enhanced by the disruption of the ectD and ectR genes in M. alcaliphilum 20Z under optimized conditions favoring ectoine accumulation. We demonstrated effective genetic engineering in a methanotrophic bacterium, with enhanced production of ectoine from methane as the sole carbon source. This study suggests a potentially transformational path to commercial sugar-based ectoine production. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02104-2.
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23
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Enuh BM, Nural Yaman B, Tarzi C, Aytar Çelik P, Mutlu MB, Angione C. Whole-genome sequencing and genome-scale metabolic modeling of Chromohalobacter canadensis 85B to explore its salt tolerance and biotechnological use. Microbiologyopen 2022; 11:e1328. [PMID: 36314754 PMCID: PMC9597258 DOI: 10.1002/mbo3.1328] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 10/01/2022] [Indexed: 11/06/2022] Open
Abstract
Salt tolerant organisms are increasingly being used for the industrial production of high-value biomolecules due to their better adaptability compared to mesophiles. Chromohalobacter canadensis is one of the early halophiles to show promising biotechnology potential, which has not been explored to date. Advanced high throughput technologies such as whole-genome sequencing allow in-depth insight into the potential of organisms while at the frontiers of systems biology. At the same time, genome-scale metabolic models (GEMs) enable phenotype predictions through a mechanistic representation of metabolism. Here, we sequence and analyze the genome of C. canadensis 85B, and we use it to reconstruct a GEM. We then analyze the GEM using flux balance analysis and validate it against literature data on C. canadensis. We show that C. canadensis 85B is a metabolically versatile organism with many features for stress and osmotic adaptation. Pathways to produce ectoine and polyhydroxybutyrates were also predicted. The GEM reveals the ability to grow on several carbon sources in a minimal medium and reproduce osmoadaptation phenotypes. Overall, this study reveals insights from the genome of C. canadensis 85B, providing genomic data and a draft GEM that will serve as the first steps towards a better understanding of its metabolism, for novel applications in industrial biotechnology.
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Affiliation(s)
- Blaise Manga Enuh
- Biotechnology and Biosafety Department, Graduate and Natural Applied ScienceEskişehir Osmangazi UniversityEskişehirTurkey
| | - Belma Nural Yaman
- Biotechnology and Biosafety Department, Graduate and Natural Applied ScienceEskişehir Osmangazi UniversityEskişehirTurkey,Department of Biomedical Engineering, Faculty of Engineering and ArchitectureEskişehir Osmangazi UniversityEskişehirTurkey
| | - Chaimaa Tarzi
- School of Computing, Engineering & Digital TechnologiesTeesside UniversityMiddlesbroughUK
| | - Pınar Aytar Çelik
- Biotechnology and Biosafety Department, Graduate and Natural Applied ScienceEskişehir Osmangazi UniversityEskişehirTurkey,Environmental Protection and Control ProgramEskişehir Osmangazi UniversityEskişehirTurkey
| | - Mehmet Burçin Mutlu
- Department of Biology, Faculty of ScienceEskisehir Technical UniversityEskisehirTurkey
| | - Claudio Angione
- School of Computing, Engineering & Digital TechnologiesTeesside UniversityMiddlesbroughUK,Centre for Digital InnovationTeesside UniversityMiddlesbroughUK,National Horizons CentreTeesside UniversityDarlingtonUK
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24
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Yu J, Wang Z, Wang J, Mohisn A, Liu H, Zhang Y, Zhuang Y, Guo M. Physiological metabolic topology analysis of Halomonas elongata DSM 2581 T in response to sodium chloride stress. Biotechnol Bioeng 2022; 119:3509-3525. [PMID: 36062959 DOI: 10.1002/bit.28222] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 11/06/2022]
Abstract
The halophilic bacterium Halomonas elongata DSM 2581T generally adapts well to high level of salinity by biosynthesizing ectoine, which functions as an important compatible solute protecting the cell against external salinity environment. Halophilic bacteria have specific metabolic activities under high-salt conditions and are gradually applied in various industries. The present study focuses on investigating the physiological and metabolic mechanism of Halomonas elongata DSM 2581T driven by the external salinity environment. The physiological metabolic dynamics under salt stress were investigated to evaluate the effect of NaCl stress on the metabolism of H. elongata. The obtained results demonstrated that ectoine biosynthesis transited from a non-growth-related process to a growth-related process when the NaCl concentration varied from 1% to 13% (w/v). The maximum biomass (Xm =41.37 g/L), and highest ectoine production (Pm =12.91 g/L) were achieved under 8% NaCl. Moreover, the maximum biomass (Xm ) and the maximum specific growth rates (μm ) showed a first rising and then declining trend with the increased NaCl stress. Furthermore, the transcriptome analysis of H. elongata under different NaCl concentrations demonstrated that both 8% and 13% NaCl conditions resulted in increased expressions of genes involved in the pentose phosphate pathway (PPP), Entner-Doudoroff (ED) pathway, Flagellar assembly pathway and ectoine metabolism, but negatively affected the tricarboxylic acid (TCA) cycle and Fatty acid metabolism. At last, the proposed possible adaptation mechanism under the optimum NaCl concentration in H. elongata was described. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Junxiong Yu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Zejian Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Jing Wang
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Ali Mohisn
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Hao Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Yue Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Yingping Zhuang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
| | - Meijin Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237, China
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25
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Hobmeier K, Oppermann M, Stasinski N, Kremling A, Pflüger-Grau K, Kunte HJ, Marin-Sanguino A. Metabolic engineering of Halomonas elongata: Ectoine secretion is increased by demand and supply driven approaches. Front Microbiol 2022; 13:968983. [PMID: 36090101 PMCID: PMC9453808 DOI: 10.3389/fmicb.2022.968983] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 07/29/2022] [Indexed: 11/30/2022] Open
Abstract
The application of naturally-derived biomolecules in everyday products, replacing conventional synthetic manufacturing, is an ever-increasing market. An example of this is the compatible solute ectoine, which is contained in a plethora of treatment formulations for medicinal products and cosmetics. As of today, ectoine is produced in a scale of tons each year by the natural producer Halomonas elongata. In this work, we explore two complementary approaches to obtain genetically improved producer strains for ectoine production. We explore the effect of increased precursor supply (oxaloacetate) on ectoine production, as well as an implementation of increased ectoine demand through the overexpression of a transporter. Both approaches were implemented on an already genetically modified ectoine-excreting strain H. elongata KB2.13 (ΔteaABC ΔdoeA) and both led to new strains with higher ectoine excretion. The supply driven approach led to a 45% increase in ectoine titers in two different strains. This increase was attributed to the removal of phosphoenolpyruvate carboxykinase (PEPCK), which allowed the conversion of 17.9% of the glucose substrate to ectoine. For the demand driven approach, we investigated the potential of the TeaBC transmembrane proteins from the ectoine-specific Tripartite ATP-Independent Periplasmic (TRAP) transporter as export channels to improve ectoine excretion. In the absence of the substrate-binding protein TeaA, an overexpression of both subunits TeaBC facilitated a three-fold increased excretion rate of ectoine. Individually, the large subunit TeaC showed an approximately five times higher extracellular ectoine concentration per dry weight compared to TeaBC shortly after its expression was induced. However, the detrimental effect on growth and ectoine titer at the end of the process hints toward a negative impact of TeaC overexpression on membrane integrity and possibly leads to cell lysis. By using either strategy, the ectoine synthesis and excretion in H. elongata could be boosted drastically. The inherent complementary nature of these approaches point at a coordinated implementation of both as a promising strategy for future projects in Metabolic Engineering. Moreover, a wide variation of intracelllular ectoine levels was observed between the strains, which points at a major disruption of mechanisms responsible for ectoine regulation in strain KB2.13.
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Affiliation(s)
- Karina Hobmeier
- Professorship for Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Martin Oppermann
- Professorship for Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Natalie Stasinski
- Professorship for Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Andreas Kremling
- Professorship for Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Katharina Pflüger-Grau
- Professorship for Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Hans Jörg Kunte
- Division Biodeterioration and Reference Organisms, Bundesanstalt für Materialforschung und-prüfung (BAM), Berlin, Germany
| | - Alberto Marin-Sanguino
- Professorship for Systems Biotechnology, Technical University of Munich, Garching, Germany
- Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
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26
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Srivastava AK, Srivastava R, Sharma A, Bharati AP, Yadav J, Singh AK, Tiwari PK, Srivatava AK, Chakdar H, Kashyap PL, Saxena AK. Transcriptome Analysis to Understand Salt Stress Regulation Mechanism of Chromohalobacter salexigens ANJ207. Front Microbiol 2022; 13:909276. [PMID: 35847097 PMCID: PMC9279137 DOI: 10.3389/fmicb.2022.909276] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/08/2022] [Indexed: 11/21/2022] Open
Abstract
Soil salinity is one of the major global issues affecting soil quality and agricultural productivity. The plant growth-promoting halophilic bacteria that can thrive in regions of high salt (NaCl) concentration have the ability to promote the growth of plants in salty environments. In this study, attempts have been made to understand the salinity adaptation of plant growth-promoting moderately halophilic bacteria Chromohalobacter salexigens ANJ207 at the genetic level through transcriptome analysis. In order to identify the stress-responsive genes, the transcriptome sequencing of C. salexigens ANJ207 under different salt concentrations was carried out. Among the 8,936 transcripts obtained, 93 were upregulated while 1,149 were downregulated when the NaCl concentration was increased from 5 to 10%. At 10% NaCl concentration, genes coding for lactate dehydrogenase, catalase, and OsmC-like protein were upregulated. On the other hand, when salinity was increased from 10 to 25%, 1,954 genes were upregulated, while 1,287 were downregulated. At 25% NaCl, genes coding for PNPase, potassium transporter, aconitase, excinuclease subunit ABC, and transposase were found to be upregulated. The quantitative real-time PCR analysis showed an increase in the transcript of genes related to the biosynthesis of glycine betaine coline genes (gbcA, gbcB, and L-pro) and in the transcript of genes related to the uptake of glycine betaine (OpuAC, OpuAA, and OpuAB). The transcription of the genes involved in the biosynthesis of L-hydroxyproline (proD and proS) and one stress response proteolysis gene for periplasmic membrane stress sensing (serP) were also found to be increased. The presence of genes for various compatible solutes and their increase in expression at the high salt concentration indicated that a coordinated contribution by various compatible solutes might be responsible for salinity adaptation in ANJ207. The investigation provides new insights into the functional roles of various genes involved in salt stress tolerance and oxidative stress tolerance produced by high salt concentration in ANJ207 and further support the notion regarding the utilization of bacterium and their gene(s) in ameliorating salinity problem in agriculture.
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Affiliation(s)
- Alok Kumar Srivastava
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Ruchi Srivastava
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Anjney Sharma
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Akhilendra Pratap Bharati
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India.,Department of Life Science and Biotechnology, Chhatrapati Shahu Ji Maharaj University, Kanpur, India
| | - Jagriti Yadav
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Alok Kumar Singh
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Praveen Kumar Tiwari
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Anchal Kumar Srivatava
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Hillol Chakdar
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
| | - Prem Lal Kashyap
- Indian Council of Agricultural Research-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Anil Kumar Saxena
- Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India
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27
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Deficiency of exopolysaccharides and O-antigen makes Halomonas bluephagenesis self-flocculating and amenable to electrotransformation. Commun Biol 2022; 5:623. [PMID: 35750760 PMCID: PMC9232590 DOI: 10.1038/s42003-022-03570-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/08/2022] [Indexed: 11/17/2022] Open
Abstract
Halomonas bluephagenesis, a haloalkaliphilic bacterium and native polyhydroxybutyrate (PHB) producer, is a non-traditional bioproduction chassis for the next generation industrial biotechnology (NGIB). A single-sgRNA CRISPR/Cas9 genome editing tool is optimized using dual-sgRNA strategy to delete large DNA genomic fragments (>50 kb) with efficiency of 12.5% for H. bluephagenesis. The non-essential or redundant gene clusters of H. bluephagenesis, including those encoding flagella, exopolysaccharides (EPSs) and O-antigen, are sequentially deleted using this improved genome editing strategy. Totally, ~3% of the genome is reduced with its rapid growth and high PHB-production ability unaffected. The deletion of EPSs and O-antigen gene clusters shows two excellent properties from industrial perspective. Firstly, the EPSs and O-antigen deleted mutant rapidly self-flocculates and precipitates within 20 min without centrifugation. Secondly, DNA transformation into the mutant using electroporation becomes feasible compared to the wild-type H. bluephagenesis. The genome-reduced H. bluephagenesis mutant reduces energy and carbon source requirement to synthesize PHB comparable to its wild type. The H. bluephagenesis chassis with a reduced genome serves as an improved version of a NGIB chassis for productions of polyhydroxyalkanoates (PHA) or other chemicals. CRISPR/Cas9 editing of a PHB-producing H. bluephagenesis strain is used to delete the redundant synthesis pathways of flagella and EPSs, allowing for enhanced self-flocculation, less carbon and energy requirement for metabolic processes and feasible electrotransformation.
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28
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Chen SY, Peng TC, Huang SZ, Chien CC. Isolation of an ectoine-producing Sinobaca sp. and identification of genes that are involved in ectoine biosynthesis. FEMS Microbiol Lett 2022; 369:6596284. [PMID: 35641156 DOI: 10.1093/femsle/fnac046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 04/07/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
A moderate halophilic bacterium that could accumulate ectoine and hydroxyectoine was isolated from soil near a salt mine and was identified as a Sinobaca sp. (designed strain H24) according to 16S rRNA gene sequence analysis. The bacterium grew well in the presence of 1 to 2 M NaCl, while growth in a medium that contained 2 M NaCl led to higher accumulation of ectoines. The yields of ectoine and hydroxyectoine by Sinobaca sp. H24 reached 11.27 mg/L and 1.34 mg/L, respectively, when cultured in the following medium: NaCl (2 M), peptone (5 g/L), yeast extract (1 g/L), NH4Cl (0.02 M), KH2PO4 (1 M), K2HPO4 (0.1 M) and glycerol (1% w/v). Genes that are involved in ectoine biosynthesis of Sinobaca sp. H24 were also identified, and their sequences were determined by a metagenomics approach. The results demonstrated that Sinobaca sp. H24 possesses ectoine metabolism genes for both ectoine biosynthesis (ectA, ectB, ectC and ectD) and ectoine degradation (doeA). Genes that are related to ectoine biosynthesis, such as lysC and asd, were also characterized. The identification and characterization results for ectoine/hydroxyectoine biosynthesis genes are in agreement with the physiology of Sinobaca sp. H24 as a potential candidate for ectoine production for industrial applications. This report established for the first time the accumulation of ectoine/hydroxyectoine in Sinobaca sp. and characterized the genes that are involved in ectoine/hydroxyectoine biosynthesis in Sinobaca sp. H24.
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Affiliation(s)
- Shan-Yu Chen
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan, Taiwan
| | - Tzu-Chia Peng
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan, Taiwan
| | - Shan-Ze Huang
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan, Taiwan
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan, Taiwan
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29
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Hobmeier K, Cantone M, Nguyen QA, Pflüger-Grau K, Kremling A, Kunte HJ, Pfeiffer F, Marin-Sanguino A. Adaptation to Varying Salinity in Halomonas elongata: Much More Than Ectoine Accumulation. Front Microbiol 2022; 13:846677. [PMID: 35432243 PMCID: PMC9006882 DOI: 10.3389/fmicb.2022.846677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
The halophilic γ-proteobacterium Halomonas elongata DSM 2581 T thrives at salt concentrations well above 10 % NaCl (1.7 M NaCl). A well-known osmoregulatory mechanism is the accumulation of the compatible solute ectoine within the cell in response to osmotic stress. While ectoine accumulation is central to osmoregulation and promotes resistance to high salinity in halophilic bacteria, ectoine has this effect only to a much lesser extent in non-halophiles. We carried out transcriptome analysis of H. elongata grown on two different carbon sources (acetate or glucose), and low (0.17 M NaCl), medium (1 M), and high salinity (2 M) to identify additional mechanisms for adaptation to high saline environments. To avoid a methodological bias, the transcripts were evaluated by applying two methods, DESeq2 and Transcripts Per Million (TPM). The differentially transcribed genes in response to the available carbon sources and salt stress were then compared to the transcriptome profile of Chromohalobacter salexigens, a closely related moderate halophilic bacterium. Transcriptome profiling supports the notion that glucose is degraded via the cytoplasmic Entner-Doudoroff pathway, whereas the Embden-Meyerhoff-Parnas pathway is employed for gluconeogenesis. The machinery of oxidative phosphorylation in H. elongata and C. salexigens differs greatly from that of non-halophilic organisms, and electron flow can occur from quinone to oxygen along four alternative routes. Two of these pathways via cytochrome bo' and cytochrome bd quinol oxidases seem to be upregulated in salt stressed cells. Among the most highly regulated genes in H. elongata and C. salexigens are those encoding chemotaxis and motility proteins, with genes for chemotaxis and flagellar assembly severely downregulated at low salt concentrations. We also compared transcripts at low and high-salt stress (low growth rate) with transcripts at optimal salt concentration and found that the majority of regulated genes were down-regulated in stressed cells, including many genes involved in carbohydrate metabolism, while ribosome synthesis was up-regulated, which is in contrast to what is known from non-halophiles at slow growth. Finally, comparing the acidity of the cytoplasmic proteomes of non-halophiles, extreme halophiles and moderate halophiles suggests adaptation to an increased cytoplasmic ion concentration of H. elongata. Taken together, these results lead us to propose a model for salt tolerance in H. elongata where ion accumulation plays a greater role in salt tolerance than previously assumed.
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Affiliation(s)
- Karina Hobmeier
- Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Martina Cantone
- Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Quynh Anh Nguyen
- Systems Biotechnology, Technical University of Munich, Garching, Germany
| | | | - Andreas Kremling
- Systems Biotechnology, Technical University of Munich, Garching, Germany
| | - Hans Jörg Kunte
- Division Biodeterioration and Reference Organisms, Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | - Friedhelm Pfeiffer
- Computational Biology Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Alberto Marin-Sanguino
- Systems Biotechnology, Technical University of Munich, Garching, Germany.,Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
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30
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Dai T, Wang Y, Yang G. Visualization of DNA Damage and Protection by Atomic Force Microscopy in Liquid. Int J Mol Sci 2022; 23:ijms23084388. [PMID: 35457204 PMCID: PMC9025965 DOI: 10.3390/ijms23084388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/06/2022] [Accepted: 04/12/2022] [Indexed: 11/16/2022] Open
Abstract
DNA damage is closely related to cancer and many aging-related diseases. Peroxynitrite is a strong oxidant, thus a typical DNA damage agent, and is a major mediator of the inflammation-associated pathogenesis. For the first time, we directly visualized the process of DNA damage by peroxynitrite and DNA protection by ectoine via atomic force microscopy in liquid. We found that the persistence length of DNA decreases significantly by adding a small amount of peroxynitrite, but the observed DNA chains are still intact. Specifically, the persistence length of linear DNA in a low concentration of peroxynitrite (0 µM to 200 µM) solution decreases from about 47 nm to 4 nm. For circular plasmid DNA, we observed the enhanced superhelices of plasmid DNA due to the chain soften. When the concentration of peroxynitrite was above 300 µM, we observed the fragments of DNA. Interestingly, we also identified single-stranded DNAs during the damage process, which is also confirmed by ultraviolet spectroscopy. However, if we added 500 mM ectoine to the high concentration PN solution, almost no DNA fragments due to double strand breaks were observed because of the protection of ectoine. This protection is consistent with the similar effect for DNA damage caused by ionizing radiation and oxygenation. We ascribe DNA protection to the preferential hydration of ectoine.
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Affiliation(s)
| | - Yanwei Wang
- Correspondence: (Y.W.); (G.Y.); Tel.: +86-577-8668-9033 (Y.W. & G.Y.); Fax: +86-577-8668-9010 (Y.W. & G.Y.)
| | - Guangcan Yang
- Correspondence: (Y.W.); (G.Y.); Tel.: +86-577-8668-9033 (Y.W. & G.Y.); Fax: +86-577-8668-9010 (Y.W. & G.Y.)
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31
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Martínez GM, Pire C, Martínez-Espinosa RM. Hypersaline environments as natural sources of microbes with potential applications in biotechnology: the case of solar evaporation systems to produce salt in Alicante County (Spain). CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100136. [PMID: 35909606 PMCID: PMC9325878 DOI: 10.1016/j.crmicr.2022.100136] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 04/14/2022] [Accepted: 04/24/2022] [Indexed: 11/18/2022] Open
Affiliation(s)
- Guillermo Martínez Martínez
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Ap. 99, Alicante, E-03080 Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Ap. 99, Alicante, E-03080 Spain
| | - Carmen Pire
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Ap. 99, Alicante, E-03080 Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Ap. 99, Alicante, E-03080 Spain
| | - Rosa María Martínez-Espinosa
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Ap. 99, Alicante, E-03080 Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Ap. 99, Alicante, E-03080 Spain
- Corresponding author.
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32
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Zhang T, Cui T, Cao Y, Li Y, Li F, Zhu D, Xing J. Whole genome sequencing of the halophilic Halomonas qaidamensis XH36, a novel species strain with high ectoine production. Antonie Van Leeuwenhoek 2022; 115:545-559. [PMID: 35243586 DOI: 10.1007/s10482-022-01709-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 01/18/2022] [Indexed: 10/18/2022]
Abstract
Here, we report the whole genome of a novel halophilic Halomonas species strain XH36 with high ectoine production potential. The genome was 3,818,310 bp in size with a GC content of 51.97%, and contained 3533 genes, 61 tRNAs and 18 rRNAs. The phylogenetic analysis using the 16s rRNA genes, the UBCGs and the TYGS database indicated that XH36 belongs to a novel Halomonas species, which we named as Halomonas qaidamensis. Osmoadaptation related genes including Na(+) and K(+) transport and compatible solute accumulation were both present in the XH36 genome, the latter of which mainly contained ectoine, 5-hydroxyectoine and betaine. HPLC validation studies showed that H. qaidamensis XH36 accumulated ectoine to cope with salt stress, and the content of ectoine could be as high as 315 mg/g CDW under 3 mol/l NaCl. Our results show that XH36 is a new promising industrial strain for ectoine production, and the genomic analysis will guide us to better understand its salt-induced osmoadaptation mechanisms, and provide theoretical references for future application research of ectoine.
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Affiliation(s)
- Tiantian Zhang
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China
| | - Tianqi Cui
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China
| | - Yaning Cao
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China
| | - Yongzhen Li
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China
| | - Fenghui Li
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China
| | - Derui Zhu
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China
| | - Jiangwa Xing
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, China.
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33
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Tsuji A, Takei Y, Nishimura T, Azuma Y. Identification of New Halomonas Strains from Food-related Environments. Microbes Environ 2022; 37. [PMID: 35296582 PMCID: PMC8958296 DOI: 10.1264/jsme2.me21052] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Halomonas species, which are aerobic, alkaliphilic, and moderately halophilic bacteria, produce diverse biochemicals. To identify food-related Halomonas strains for bioremediation and the industrial production of biochemicals, 20 strains were isolated from edible seashells, shrimp, and umeboshi (pickled Japanese plum) factory effluents. All isolates were phylogenetically classified into a large clade of Halomonas species. Most isolates, which grew in wide pH (6–13) and salt concentration (0–14%) ranges, exhibited the intracellular accumulation of poly(3-hydroxybutyrate) granules. The characteristics of these isolates varied. A020 isolated from umeboshi factory effluents exhibited enhanced stress tolerance and proliferation and comprised two plasmids. IMZ03 and A020 grew to more than 200 OD600, while IMZ03 produced 3.5% 3-hydroxybutyrate in inorganic medium supplemented with 10% sucrose. The mucus of TK1-1 cultured on agar medium comprised approximately 64 mM of ectoine. Whole-genome sequencing of A020 was performed to elucidate its origin and genomic characteristics. The genome analysis revealed a region exhibiting synteny with a large virus genome isolated from the ocean, but did not identify any predictable pathogenic genes. Therefore, saline foods and related materials may be suitable resources for isolating Halomonas strains exhibiting unique, useful, and innocuous features.
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Affiliation(s)
- Ayaka Tsuji
- Graduate School of Biology-Oriented Science and Technology, Kindai University
| | - Yasuko Takei
- Graduate School of Biology-Oriented Science and Technology, Kindai University
| | | | - Yoshinao Azuma
- Graduate School of Biology-Oriented Science and Technology, Kindai University
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34
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Zhang T, Zhang X, Li Y, Yang N, Qiao L, Miao Z, Xing J, Zhu D. Study of osmoadaptation mechanisms of halophilic Halomonas alkaliphila XH26 under salt stress by transcriptome and ectoine analysis. Extremophiles 2022; 26:14. [PMID: 35229247 DOI: 10.1007/s00792-022-01256-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 01/04/2022] [Indexed: 11/04/2022]
Abstract
Halophilic bacteria such as the genus Halomonas are promising candidates in diverse industrial, agricultural and biomedical applications. Here, we successfully isolated a halophilic Halomonas alkaliphila strain XH26 from Xiaochaidan Salt Lake, and studied its osmoadaptation strategies using transcriptome and ectoine analysis. Divergent mechanisms were involved in osmoadaptation at different salinities in H. alkaliphila XH26. At moderate salinity (6% NaCl), increased transcriptions of ABC transporters related to iron (III), phosphate, phosphonate, monosaccharide and oligosaccharide import were observed. At high salinity (15% NaCl), transcriptions of flagellum assembly and cell motility were significantly inhibited. The transcriptional levels of ABC transporter genes related to iron (III) and iron3+-hydroxamate import, glycine betaine and putrescine uptake, and cytochrome biogenesis and assembly were significantly up-regulated. Ectoine synthesis and accumulation was significantly increased under salt stress, and the increased transcriptional expressions of ectoine synthesis genes ectB and ectC may play a key role in high salinity induced osmoadaptation. At extreme high salinity (18% NaCl), 5-hydroxyectoine and ectoine worked together to maintain cell survival. Together these results give valuable insights into the osmoadaptation mechanisms of H. alkaliphila XH26, and provide useful information for further engineering this specific strain for increased ectoine synthesis and related applications.
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Affiliation(s)
- Tiantian Zhang
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China
| | - Xin Zhang
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China
| | - Yongzhen Li
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China
| | - Ning Yang
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China
| | - Lijuan Qiao
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China
| | - Zengqiang Miao
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China
| | - Jiangwa Xing
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China.
| | - Derui Zhu
- Research Centre of Basic Medical Sciences, Medical College, Qinghai University, Xining, 810016, People's Republic of China.
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35
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Draft Genome Sequence of a Bacterium Isolated from Hypersaline Soil in Sonora, Mexico: Halomonas sp. Strain BLLS135. Microbiol Resour Announc 2022; 11:e0140920. [PMID: 35175110 PMCID: PMC8852318 DOI: 10.1128/mra.01409-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Halomonas sp. strain BLLS135 was isolated from hypersaline soil in Mexico. Here, we present the draft genome of this strain. Its genome has 2,861 protein-coding genes, 63 tRNAs, two 16S rRNAs, five 5S rRNAs, and a single copy of 23S rRNA, with a GC content of 63.5%.
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36
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Zhang H, Liang Z, Zhao M, Ma Y, Luo Z, Li S, Xu H. Metabolic Engineering of Escherichia coli for Ectoine Production With a Fermentation Strategy of Supplementing the Amino Donor. Front Bioeng Biotechnol 2022; 10:824859. [PMID: 35145959 PMCID: PMC8822159 DOI: 10.3389/fbioe.2022.824859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Ectoine, an osmotic pressure-compensated solute, is used in the food, agriculture, medicine, and cosmetics industries due to its ability to protect macromolecules. In this study, an ectoine-producing variant of Escherichia coli, ET08, was genetically constructed by introducing the ectABC gene cluster and eliminating metabolic pathways involving lysine and pyruvate. Medium optimization enhanced ectoine production from 1.87 to 10.2 g/L. Analysis of the transcriptional levels revealed that supplementation with ammonium sulfate enhanced the metabolic flux towards the biosynthesis of ectoine. Furthermore, by optimizing the copy number of ectA, ectB, and ectC, the recombinant E. coli ET11 (ectA:ectB:ectC = 1:2:1) produced 12.9 g/L ectoine in the shake flask and 53.2 g/L ectoine in a fed-batch fermenter, representing the highest ectoine titer produced by E. coli, which has great industrial prospects.
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Affiliation(s)
- Hao Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Zhong Liang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Ming Zhao
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Yanqin Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Zhengshan Luo
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
- *Correspondence: Sha Li, ; Hong Xu,
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
- Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, China
- *Correspondence: Sha Li, ; Hong Xu,
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37
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Hermann L, Dempwolff F, Steinchen W, Freibert SA, Smits SHJ, Seubert A, Bremer E. The MocR/GabR Ectoine and Hydroxyectoine Catabolism Regulator EnuR: Inducer and DNA Binding. Front Microbiol 2022; 12:764731. [PMID: 35003002 PMCID: PMC8739950 DOI: 10.3389/fmicb.2021.764731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 12/01/2021] [Indexed: 11/26/2022] Open
Abstract
The compatible solutes ectoine and 5-hydroxyectoine are widely synthesized by bacteria as osmostress protectants. These nitrogen-rich tetrahydropyrimidines can also be exploited as nutrients by microorganisms. Many ectoine/5-hydroxyectoine catabolic gene clusters are associated with a regulatory gene (enuR: ectoine nutrient utilization regulator) encoding a repressor protein belonging to the MocR/GabR sub-family of GntR-type transcription factors. Focusing on EnuR from the marine bacterium Ruegeria pomeroyi, we show that the dimerization of EnuR is mediated by its aminotransferase domain. This domain can fold independently from its amino-terminal DNA reading head and can incorporate pyridoxal-5′-phosphate (PLP) as cofactor. The covalent attachment of PLP to residue Lys302 of EnuR was proven by mass-spectrometry. PLP interacts with system-specific, ectoine and 5-hydroxyectoine-derived inducers: alpha-acetyldiaminobutyric acid (alpha-ADABA), and hydroxy-alpha-acetyldiaminobutyric acid (hydroxy-alpha-ADABA), respectively. These inducers are generated in cells actively growing with ectoines as sole carbon and nitrogen sources, by the EutD hydrolase and targeted metabolic analysis allowed their detection. EnuR binds these effector molecules with affinities in the low micro-molar range. Studies addressing the evolutionary conservation of EnuR, modelling of the EnuR structure, and docking experiments with the inducers provide an initial view into the cofactor and effector binding cavity. In this cavity, the two high-affinity inducers for EnuR, alpha-ADABA and hydroxy-alpha-ADABA, are positioned such that their respective primary nitrogen group can chemically interact with PLP. Purified EnuR bound with micro-molar affinity to a 48 base pair DNA fragment containing the sigma-70 type substrate-inducible promoter for the ectoine/5-hydroxyectoine importer and catabolic gene cluster. Consistent with the function of EnuR as a repressor, the core elements of the promoter overlap with two predicted EnuR operators. Our data lend themselves to a straightforward regulatory model for the initial encounter of EnuR-possessing ectoine/5-hydroxyectoine consumers with environmental ectoines and for the situation when the external supply of these compounds has been exhausted by catabolism.
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Affiliation(s)
- Lucas Hermann
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany.,Department of Biochemistry and Synthetic Metabolism, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
| | - Felix Dempwolff
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Wieland Steinchen
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Sven-Andreas Freibert
- Department of Medicine, Institute for Cytobiology and Cytopathology, and SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich-Heine-University, Düsseldorf, Germany.,Center for Structural Studies (CSS), Faculty of Biochemistry, Heinrich-Heine-University, Düsseldorf, Germany
| | - Andreas Seubert
- Faculty of Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Erhard Bremer
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany.,SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
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38
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Khalilova EA, Kotenko ST, Islammagomedova EA, Abakarova AA, Chernyh NА, Aliverdiyeva DA. Halophilic bacteria of salt lakes and saline soils of the Peri-Caspian lowland (Republic of Daghestan) and their biotechnological potential. Vavilovskii Zhurnal Genet Selektsii 2021; 25:224-233. [PMID: 34901720 PMCID: PMC8627887 DOI: 10.18699/vj21.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 12/02/2022] Open
Abstract
The article presents the results of studying the biodiversity and biotechnological potential of halophilic
microorganisms from the thermal highly mineralized Berikey Lake, the salty Lake Tarumovskoye and saline soils of
the Peri-Caspian Lowland (Republic of Daghestan). Denitrifying halophilic bacteria of the genus Halomonas and
Virgibacillus were identified using microbiological methods and 16S rRNA gene analysis. A new species Halomonas sp. G2 (MW386470) with a similarity of the nucleotide sequences of the 16S rRNA genes is 95 %. Strain G2 is
an extreme halophile capable of growing in the range of 5–25 % NaCl (optimum 25 %) and forming a carotenoid
pigment. Mesophil, 30–37 °С (optimum 30 °С); neutrophil, pH 6–8 (optimum 7.2–7.4). Strain G2 chemolithotroph;
reduces nitrate or nitrite as electron donors; catalase-, amylase-, protease- and β-galactosidase-positive; lipase-,
oxidase- and urease-negative. Not able to hydrolyze inositol, indole; produces lysine, gelatin, ectoine; uses citrate
and sodium malate as a source of carbon and energy; does not produce ornitin, H2S or acid from d-mannose, sucrose, glycerol, cellobiose, except for lactose and d-glucose. Susceptible to trimethoprim, ciprofloxacin, ofloxacin,
kanamycin, vancomycin, rifampicin, cefuroxime, ampicillin, ceftazidime, fosfomycin, clarithromycin, cefepime, cefaclor. The G+C content in DNA is 67.3 %. A distinctive characteristic of the isolate was the production of industrially significant hydrolytic enzymes such as amylase, protease, β-galactosidase, and oxidoreductase (catalase) at a
NaCl concentration of 25 % in the medium. Habitat: saline soils on the territory of the Tersko-Kumskaya lowland
(Republic of Daghestan, Russia). The rest of the halophilic isolates of H. ventosae G1 (MW386469), H. elongata G3
(MW386471), V. salinarius B2 (MW386472), and V. salinarius B3 (MW386473) had a high degree of similarity (100 %)
with the type strains of H. elongata DSM 2581Т
and V. salarius DSM 18441Т
; the content of G+C in DNA was 65.8,
66.5, 42.8 and 37.3 %, respectively. The strains had a high biotechnological potential at NaCl concentrations of 5 and
25 % in the medium. The data obtained expanded the understanding of the diversity and ecological significance
of denitrifying bacteria in the functioning of arid ecosystems and make it possible to identify strains producing
enzymes of industrial importance.
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Affiliation(s)
- E A Khalilova
- Precaspian Institute of Biological Resources of the Daghestan Federal Research Center of the Russian Academy of Sciences, Makhachkala, Daghestan, Russia
| | - S T Kotenko
- Precaspian Institute of Biological Resources of the Daghestan Federal Research Center of the Russian Academy of Sciences, Makhachkala, Daghestan, Russia
| | - E A Islammagomedova
- Precaspian Institute of Biological Resources of the Daghestan Federal Research Center of the Russian Academy of Sciences, Makhachkala, Daghestan, Russia
| | - A A Abakarova
- Precaspian Institute of Biological Resources of the Daghestan Federal Research Center of the Russian Academy of Sciences, Makhachkala, Daghestan, Russia
| | - N А Chernyh
- Winogradsky Institute of Microbiology, Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Moscow, Russia
| | - D A Aliverdiyeva
- Precaspian Institute of Biological Resources of the Daghestan Federal Research Center of the Russian Academy of Sciences, Makhachkala, Daghestan, Russia
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39
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Kang JY, Lee B, Kim JA, Kim MS, Kim CH. Identification and characterization of an ectoine biosynthesis gene cluster from Aestuariispira ectoiniformans sp. nov., isolated from seawater. Microbiol Res 2021; 254:126898. [PMID: 34710834 DOI: 10.1016/j.micres.2021.126898] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 09/16/2021] [Accepted: 10/19/2021] [Indexed: 11/26/2022]
Abstract
An ectoine-producing bacterium, designated SWCN16T, was isolated from seawater and could be grown in a medium containing up to 12 % NaCl. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SWCN16T belonged to the genus Aestuariispira, class Alphaproteobacteria, and shared the highest 16S rRNA gene sequence similarity of 96.8% with Aestuariispira insulae CECT 8488T. The phenotypic, chemotaxonomic, and genotypic characteristics findings of this study suggested that strain SWCN16T represented a novel species of the genus Aestuariispira. We propose the name Aestuariispira ectoiniformans sp. nov. for this species. Whole-genome sequencing analysis of the isolate revealed a putative ectABC gene cluster for ectoine biosynthesis. These genes were found to be functional using ectoine synthesis testing and S16-ectBAC cells, which were pET21a-ectBAC-transformed E. coli BL21 cells. We found that S16-ectBAC synthesized about 1.67 g/L extracellular ectoine and about 0.59 g/L intracellular ectoine via bioconversion at optimum conditions.
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Affiliation(s)
- Ji Young Kang
- Industrial Microbiology and Bioprocess Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, 580-185, Republic of Korea.
| | - Binna Lee
- Industrial Microbiology and Bioprocess Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, 580-185, Republic of Korea.
| | - Jeong Ah Kim
- Industrial Microbiology and Bioprocess Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, 580-185, Republic of Korea.
| | - Min-Soo Kim
- Industrial Microbiology and Bioprocess Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, 580-185, Republic of Korea.
| | - Chul Ho Kim
- Industrial Microbiology and Bioprocess Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, 580-185, Republic of Korea.
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40
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Ma Q, Xia L, Wu H, Zhuo M, Yang M, Zhang Y, Tan M, Zhao K, Sun Q, Xu Q, Chen N, Xie X. Metabolic engineering of Escherichia coli for efficient osmotic stress-free production of compatible solute hydroxyectoine. Biotechnol Bioeng 2021; 119:89-101. [PMID: 34612520 DOI: 10.1002/bit.27952] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/22/2021] [Accepted: 09/28/2021] [Indexed: 11/08/2022]
Abstract
Compatible solutes are key for the ability of halophilic bacteria to resist high osmotic stress. They have received wide attention from researchers for their excellent osmotic protection properties. Hydroxyectoine is a particularly important compatible solute, but its production by microbes faces several challenges, including low titer/yield, the presence of the byproduct ectoine, and the requirement of high salinity. Here, we aimed to metabolically engineer Escherichia coli to efficiently produce hydroxyectoine in the absence of osmotic stress without accumulating the byproduct ectoine. First, combinatorial optimization of the expression strength of key genes in the ectoine synthesis module and hydroxyectoine synthesis module was conducted. After optimization of the expression of these genes, 12.12 g/L hydroxyectoine and 0.24 g/L ectoine were obtained at 36 h in shake-flask fermentation with the addition of the co-substrate α-ketoglutarate. Further optimization of the addition of α-ketoglutarate achieved the sole production of hydroxyectoine (i.e., no ectoine accumulation), indicating that the supply of α-ketoglutarate is critically important for sole hydroxyectoine production. Finally, quorum sensing-based auto-regulation of intracellular α-ketoglutarate pool was implemented as an alternative to α-ketoglutarate addition by coupling the expression of sucA with the esaI/esaR circuit, which led to 14.93 g/L hydroxyectoine with a unit cell yield of 1.678 g/g and no ectoine accumulation in the absence of osmotic stress. This is the highest reported titer of sole hydroxyectoine production under salinity-free fermentation to date.
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Affiliation(s)
- Qian Ma
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Li Xia
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Heyun Wu
- College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, China
| | - Mingyang Zhuo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Mengya Yang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Ying Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Miao Tan
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Kexin Zhao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Quanwei Sun
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Qingyang Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Ning Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Xixian Xie
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
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Frikha-Dammak D, Ayadi H, Hakim-Rekik I, Belbahri L, Maalej S. Genome analysis of the salt-resistant Paludifilum halophilum DSM 102817 T reveals genes involved in flux-tuning of ectoines and unexplored bioactive secondary metabolites. World J Microbiol Biotechnol 2021; 37:178. [PMID: 34549358 DOI: 10.1007/s11274-021-03147-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
Paludifilum halophilum DSM 102817T is the first member of the genus Paludifilum in the Thermoactinomycetaceae family. The thermohalophilic bacterium was isolated from the solar saltern of Sfax, Tunisia and was shown to be able to produce ectoines with a relatively high-yield and to cope with salt stress conditions. In this study, the whole genome of P. halophilum was sequenced and analysed. Analysis revealed 3,789,765 base pairs with an average GC% content of 51.5%. A total of 3775 genes were predicted of which 3616 were protein-coding genes and 73 were RNA genes. The genes encoding key enzymes for ectoines (ectoine and hydroxyectoine) synthesis (ectABCD) were identified from the bacterial genome next to a gene cluster (ehuABCD) encoding a binding-protein-dependent ABC transport system responsible for ectoines mobility through the cell membrane. With the aid of KEGG analysis, we found that the central catabolic network of P. halophilum comprises the pathways of glycolysis, tricarboxylic acid cycle, and pentose phosphate. In addition, anaplerotic pathways replenishing oxaloacetate and glutamate synthesis from central metabolism needed for high ectoines biosynthetic fluxes were identified through several key enzymes. Furthermore, a total of 18 antiSMASH-predicted putative biosynthetic gene clusters for secondary metabolites with high novelty and diversity were identified in P. halophilum genome, including biosynthesis of colabomycine-A, fusaricidin-E, zwittermycin A, streptomycin, mycosubtilin and meilingmycin. Based on these data, P. halophilum emerged as a promising source for ectoines and antimicrobials with the potential to be scaled up for industrial production, which could benefit the pharmaceutical and cosmetic industries.
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Affiliation(s)
- Donyez Frikha-Dammak
- Laboratoire de Biodiversité Marine et Environnement (LR18ES30), Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia
| | - Houda Ayadi
- Laboratoire de Biodiversité Marine et Environnement (LR18ES30), Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia
| | - Imen Hakim-Rekik
- Unité de Génomique Fonctionnelle et Physiologie des Plantes, Université de Sfax, Institut Supérieur de Biotechnologie de Sfax, BP 1175, 3000, Sfax, Tunisia
| | - Lassaad Belbahri
- Laboratory of Soil Biology, University of Neuchatel, 11 Rue Emile Argand, 2000, Neuchâtel, Switzerland
| | - Sami Maalej
- Laboratoire de Biodiversité Marine et Environnement (LR18ES30), Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia.
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Andrys J, Heider J, Borowski T. Comparison of different approaches to derive classical bonded force-field parameters for a transition metal cofactor: a case study for non-heme iron site of ectoine synthase. Theor Chem Acc 2021. [DOI: 10.1007/s00214-021-02796-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractComputational investigations into the structure and function of metalloenzymes with transition metal cofactors require proper preparation of the model, which requires obtaining reliable force field parameters for the cofactor. Here, we present a test case where several methods were used to derive amber force field parameters for a bonded model of the Fe(II) cofactor of ectoine synthase. Moreover, the spin of the ground state of the cofactor was probed by DFT and post-HF methods, which consistently indicated the quintet state is lowest in energy and well separated from triplet and singlet. The performance of the obtained force field parameter sets, derived for the quintet spin state, was scrutinized and compared taking into account metrics focused on geometric features of the models as well as their energetics. The main conclusion of this study is that Hessian-based methods yield parameters which represent the geometry around the metal ion, but poorly reproduce energy variance with geometrical changes. On the other hand, the energy-based method yields parameters accurately reproducing energy-structure relationships, but with bad performance in geometry optimization. Preliminary tests show that admixing geometrical criteria to energy-based methods may allow to derive parameters with acceptable performance for both energy and geometry.
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43
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Halomonas as a chassis. Essays Biochem 2021; 65:393-403. [PMID: 33885142 PMCID: PMC8314019 DOI: 10.1042/ebc20200159] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 01/04/2023]
Abstract
With the rapid development of systems and synthetic biology, the non-model bacteria, Halomonas spp., have been developed recently to become a cost-competitive platform for producing a variety of products including polyesters, chemicals and proteins owing to their contamination resistance and ability of high cell density growth at alkaline pH and high salt concentration. These salt-loving microbes can partially solve the challenges of current industrial biotechnology (CIB) which requires high energy-consuming sterilization to prevent contamination as CIB is based on traditional chassis, typically, Escherichia coli, Bacillus subtilis, Pseudomonas putida and Corynebacterium glutamicum. The advantages and current status of Halomonas spp. including their molecular biology and metabolic engineering approaches as well as their applications are reviewed here. Moreover, a systematic strain engineering streamline, including product-based host development, genetic parts mining, static and dynamic optimization of modularized pathways and bioprocess-inspired cell engineering are summarized. All of these developments result in the term called next-generation industrial biotechnology (NGIB). Increasing efforts are made to develop their versatile cell factories powered by synthetic biology to demonstrate a new biomanufacturing strategy under open and continuous processes with significant cost-reduction on process complexity, energy, substrates and fresh water consumption.
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Wang L, Liu X, Lai Q, Gu L, Shao Z. Halomonas diversa sp. nov., isolated from deep-sea sediment of the Pacific Ocean. Int J Syst Evol Microbiol 2021; 71. [PMID: 33906704 DOI: 10.1099/ijsem.0.004790] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel Gram-stain-negative, facultatively anaerobic, rod-shaped bacterium, designated as D167-6-1T, was isolated from deep-sea sediment collected from the Pacific Ocean. The cells were catalase- and oxidase-positive, and motile by means of peritrichous flagella. Growth occurred at NaCl concentrations ranging from 0 to 19 % (optimum, 2-8 %, w/v), from pH 6 to 11 (optimum, 7-8) and at temperatures between 4 and 45 °C (optimum, 33 °C). Phylogenetic analysis based on 16S rRNA, gyrB and rpoD gene sequences and its genome sequence revealed that strain D167-6-1T formed a monophyletic branch within the genus Halomonas and was most closely related to Halomonas saliphila, Halomonas pellis, Halomonas kenyensis, Halomonas daqingensis, Halomonas desiderata and Halomonas lactosivorans (with 98.5, 98.5, 98.4, 98.1, 97.5 and 97.8 % 16S rRNA sequence similarity, respectively). The complete genome size of strain D167-6-1T was 4.49 Mb, with a DNA G+C content of 62.8 mol%. The estimated averagenucleotide identity and DNA-DNA hybridization values between strain D167-6-1T and other closely related species were 77.59-85.35 % and 22.0-30.6 %, respectively. The principal cellular fatty acids (>5 %) were C18 : 1 ω7c, C16 : 0, C19 : 0 cyclo ω8c, summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and C17 : 0 cyclo. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, aminophospholipid and two unidentified phospholipids. The predominant respiratory quinones were Q-9 and Q-8. The combined genotypic and phenotypic data show that strain D167-6-1T represents a novel species of the genus Halomonas, for which the name Halomonas diversa sp. nov. is proposed, with the type strain D167-6-1T (=MCCC 1A13316T=KCTC 72441T).
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Affiliation(s)
- Liping Wang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China.,School of Environment, Harbin Institute of Technology, Harbin, PR China
| | - Xiupian Liu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China
| | - Qiliang Lai
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China
| | - Li Gu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China
| | - Zongze Shao
- School of Environment, Harbin Institute of Technology, Harbin, PR China.,Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China
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Qiu X, Cao X, Xu G, Wu H, Tang X. Halomonas maris sp. nov., a moderately halophilic bacterium isolated from sediment in the southwest Indian Ocean. Arch Microbiol 2021; 203:3279-3285. [PMID: 33860341 DOI: 10.1007/s00203-021-02317-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/14/2021] [Accepted: 03/30/2021] [Indexed: 11/30/2022]
Abstract
A halophilic, Gram-staining-negative, rod-shaped, flagellated and motile bacterium, strain QX-1 T, was isolated from deep-sea sediment at a depth of 3332 m in the southwestern Indian Ocean. Strain QX-1 T growth was observed at 4-50 °C (optimum 37 °C), pH 5.0-11.0 (optimum pH 7.0), 3-25% NaCl (w/v; optimum 7%), and it did not grow without NaCl. A phylogenetic analysis based on the 16S rRNA gene placed strain QX-1 T in the genus Halomonas and most closely related to Halomonas sulfidaeris (97.9%), Halomonas zhaodongensis (97.8%), Halomonas songnenensis (97.6%), Halomonas hydrothermalis (97.4%), Halomonas subterranea (97.3%), Halomonas salicampi (97.1%), and Halomonas arcis (97.0%). DNA-DNA hybridization (< 26.5%) and average nucleotide identity values (< 83.5%) between strain QX-1 T and the related type strains meet the accepted criteria for a new species. The principal fatty acids (> 10%) of strain QX-1 T are C16:0 (25.5%), C17:0 cyclo (14.0%), C19:0 cyclo ω8c (18.7%), and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c, 18.1%). The polar lipids of strain QX-1 T are mainly diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid, unidentified aminophospholipid, and five unidentified lipids. The main respiratory quinone is Q-9. The G + C content of its chromosomal DNA is 54.4 mol%. Its fatty acid profile, respiratory quinones, and G + C content also support the placement of QX-1 T in the genus Halomonas. These phylogenetic, phenotypic, and chemotaxonomic analyses indicate that QX-1 T is a novel species, for which the name Halomonas maris is proposed. The type strain is QX-1 T (= MCCC 1A17875T = KCTC 82198 T = NBRC 114670 T).
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Affiliation(s)
- Xu Qiu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China.,School of Ocean Sciences, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Xiaorong Cao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Guangxin Xu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Huangming Wu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Xixiang Tang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China.
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46
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Liu M, Liu H, Shi M, Jiang M, Li L, Zheng Y. Microbial production of ectoine and hydroxyectoine as high-value chemicals. Microb Cell Fact 2021; 20:76. [PMID: 33771157 PMCID: PMC7995798 DOI: 10.1186/s12934-021-01567-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 03/16/2021] [Indexed: 12/20/2022] Open
Abstract
Ectoine and hydroxyectoine as typical representatives of compatible solutes are not only essential for extremophiles to survive in extreme environments, but also widely used in cosmetic and medical industries. Ectoine was traditionally produced by Halomonas elongata through a "bacterial milking" process, of which the marked feature is using a high-salt medium to stimulate ectoine biosynthesis and then excreting ectoine into a low-salt medium by osmotic shock. The optimal hydroxyectoine production was achieved by optimizing the fermentation process of Halomonas salina. However, high-salinity broth exacerbates the corrosion to fermenters, and more importantly, brings a big challenge to the subsequent wastewater treatment. Therefore, increasing attention has been paid to reducing the salinity of the fermentation broth but without a sacrifice of ectoine/hydroxyectoine production. With the fast development of functional genomics and synthetic biology, quite a lot of progress on the bioproduction of ectoine/hydroxyectoine has been achieved in recent years. The importation and expression of an ectoine producing pathway in a non-halophilic chassis has so far achieved the highest titer of ectoine (~ 65 g/L), while rational flux-tuning of halophilic chassis represents a promising strategy for the next-generation of ectoine industrial production. However, efficient conversion of ectoine to hydroxyectoine, which could benefit from a clearer understanding of the ectoine hydroxylase, is still a challenge to date.
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Affiliation(s)
- Mengshuang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Hui Liu
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Meng Shi
- Department of Microbiology, University of Washington, Seattle, USA
| | - Mingyue Jiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lingling Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - Yanning Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China.
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47
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Wang L, Shao Z. Aerobic Denitrification and Heterotrophic Sulfur Oxidation in the Genus Halomonas Revealed by Six Novel Species Characterizations and Genome-Based Analysis. Front Microbiol 2021; 12:652766. [PMID: 33815342 PMCID: PMC8014003 DOI: 10.3389/fmicb.2021.652766] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Bacteria of Halomonas are widely distributed in various environments and play a substantial role in the nutrient cycle. In this report, 14 strains capable of aerobic denitrification and heterotrophic sulfur oxidation were isolated from different habitats. Based on the phenotypic, genotypic, and chemotaxonomic analyses, these strains were considered to represent six novel species of the genus Halomonas, for which the names Halomonas zhangzhouensis sp. nov. type strain CXT3-11T ( = MCCC 1A11036T = KCTC 72087T), Halomonas aerodenitrificans sp. nov. CYD-9T ( = MCCC 1A11058T = KCTC 72088T), Halomonas sulfidoxydans sp. nov. CYN-1-2T ( = MCCC 1A11059T = KCTC 72089T), Halomonas ethanolica sp. nov. CYT3-1-1T ( = MCCC 1A11081T = KCTC 72090T), Halomonas sulfidivorans sp. nov. NLG_F1ET ( = MCCC 1A13718T = KCTC 72091T), and Halomonas tianxiuensis sp. nov. BC-M4-5T ( = MCCC 1A14433T = KCTC 72092T) are proposed. Intriguingly, they formed a unique group with 11 other species designated as the "H. desiderata group." To better understand their featured metabolisms, genes involved in denitrification and sulfur oxidation were analyzed, along with 193 other available genomes of the whole genus. Consistently, complete denitrification pathways were confirmed in the "H. desiderata group," in which napA, narG, nirS, norB, and nosZ genes coexist. Their nitrite reductase NirS formed a unique evolutionary lineage, distinguished from other denitrifiers in Halomonas. In addition, diverse occurrence patterns of denitrification genes were also observed in different phylogenetic clades of Halomonas. With respect to sulfur oxidation, fccAB genes involved in sulfide oxidation commonly exist in the "H. desiderata group," while sqr genes are diverse and can be found in more species; sqr genes co-occurred with fccAB in eight strains of this study, contributing to more active sulfide oxidation. Besides, the tsdA gene, which encodes an enzyme that oxidizes thiosulfate to tetrathionate, is ubiquitous in the genus Halomonas. The widespread presence of sqr/fccAB, pdo, and tsdA in Halomonas suggests that many Halomonas spp. can act as heterotrophic sulfur oxidizers. These results provide comprehensive insights into the potential of denitrification and sulfur oxidation in the whole genus of Halomonas. With regard to the global distribution of Halomonas, this report implies their unneglectable role in the biogeochemical cycle.
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Affiliation(s)
- Liping Wang
- School of Environment, Harbin Institute of Technology, Harbin, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, China
| | - Zongze Shao
- School of Environment, Harbin Institute of Technology, Harbin, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
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48
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Qiu X, Yu L, Cao X, Wu H, Xu G, Tang X. Halomonas sedimenti sp. nov., a Halotolerant Bacterium Isolated from Deep-Sea Sediment of the Southwest Indian Ocean. Curr Microbiol 2021; 78:1662-1669. [PMID: 33651187 DOI: 10.1007/s00284-021-02425-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 02/10/2021] [Indexed: 10/22/2022]
Abstract
A Gram-staining-negative, aerobic, flagellated, motile, rod-shaped, halophilic bacterium QX-2T was isolated from the deep-sea sediment of the Southwest Indian Ocean at a depth of 2699 m. Growth of the QX-2T bacteria was observed at 4-50 °C (optimum 30 °C), pH 5.0-12.0 (optimum pH 6.0) and 0%-30% NaCl (w/v) [optimum 4% (w/v)]. 16S rRNA gene sequencing revealed that strain QX-2T has the closest relationship with Halomonas titanicae DSM 22872T (98.2%). Phylogeny analysis classified the strain QX-2T into the genus Halomonas. The average nucleotide identity and DNA-DNA hybridization values between strain QX-2T and related type strains were lower than the currently accepted new species definition standards. Principal fatty acids (> 10%) determined were C16:0 (12.41%), C12:0-3OH (25.15%), summed feature 3 (C16:1 ω7c and/or C16:1 ω6c, 11.55%) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c, 16.06%). Identified polar lipids in strain QX-2T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid, unidentified aminophospholipid and five unidentified lipids (L1-L5). The main respiratory quinone was Q-9. The content of DNA G+C was determined to be 54.34 mol%. The results of phylogenetic analysis, phenotypic analysis and chemotaxonomic studies showed that strain QX-2T represents a novel species within the genus Halomonas, for which the name Halomonas sedimenti sp. nov. is proposed, with the type strain QX-2T (MCCC 1A17876T = KCTC 82199T).
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Affiliation(s)
- Xu Qiu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China.,School of Ocean Sciences, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Libo Yu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Xiaorong Cao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Huangming Wu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Guangxin Xu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Xixiang Tang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China.
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Wang L, Shao Z. Complete genome sequence of a denitrifying bacterium Halomonas sp. SS10-MC5 isolated from hydrothermal vent of Indian Ocean. Mar Genomics 2021; 58:100849. [PMID: 34217482 DOI: 10.1016/j.margen.2021.100849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/18/2021] [Accepted: 02/01/2021] [Indexed: 11/19/2022]
Abstract
A denitrifying bacterium Halomonas sp. SS10-MC5, was isolated from a deep-sea hydrothermal vent chimney sample of the Indian Ocean. Here we described the complete genome of strain SS10-MC5 which has one circular chromosome of 4,441,120 bp with a mean G + C content of 66.12 mol%. The complete genome harbors 4094 predicted protein-encoding genes, 65 tRNA genes as well as four 16S-23S-5S rRNA operons. Genes involved in denitrification, assimilation, PHA synthesis, stress response, and so on, were identified in this genome. These metabolic features and related genes revealed genetic basis for the adaptation to the marine environment, which help to further understand its adaptive evolution and ecological role in submarine hydrothermal environments.
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Affiliation(s)
- Liping Wang
- School of Environment, Harbin Institute of Technology, Harbin, China; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China
| | - Zongze Shao
- School of Environment, Harbin Institute of Technology, Harbin, China; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources; State Key Laboratory Breeding Base of Marine Genetic Resources; Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, PR China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.
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50
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Gregory GJ, Boyd EF. Stressed out: Bacterial response to high salinity using compatible solute biosynthesis and uptake systems, lessons from Vibrionaceae. Comput Struct Biotechnol J 2021; 19:1014-1027. [PMID: 33613867 PMCID: PMC7876524 DOI: 10.1016/j.csbj.2021.01.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022] Open
Abstract
Bacteria have evolved mechanisms that allow them to adapt to changes in osmolarity and some species have adapted to live optimally in high salinity environments such as in the marine ecosystem. Most bacteria that live in high salinity do so by the biosynthesis and/or uptake of compatible solutes, small organic molecules that maintain the turgor pressure of the cell. Osmotic stress response mechanisms and their regulation among marine heterotrophic bacteria are poorly understood. In this review, we discuss what is known about compatible solute metabolism and transport and new insights gained from studying marine bacteria belonging to the family Vibrionaceae.
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Affiliation(s)
| | - E. Fidelma Boyd
- Corresponding author at: Department of Biological Sciences, 341 Wolf Hall, University of Delaware, Newark, DE 19716, United States.
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