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Wang S, Liu Y, Guo H, Meng Y, Xiong W, Liu R, Yang C. Establishment of low-cost production platforms of polyhydroxyalkanoate bioplastics from Halomonas cupida J9. Biotechnol Bioeng 2024. [PMID: 38587130 DOI: 10.1002/bit.28694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/05/2024] [Accepted: 02/27/2024] [Indexed: 04/09/2024]
Abstract
Microbial production of polyhydroxyalkanoate (PHA) is greatly restricted by high production cost arising from high-temperature sterilization and expensive carbon sources. In this study, a low-cost PHA production platform was established from Halomonas cupida J9. First, a marker-less genome-editing system was developed in H. cupida J9. Subsequently, H. cupida J9 was engineered to efficiently utilize xylose for PHA biosynthesis by introducing a new xylose metabolism module and blocking xylonate production. The engineered strain J9UΔxylD-P8xylA has the highest PHA yield (2.81 g/L) obtained by Halomonas with xylose as the sole carbon source so far. This is the first report on the production of short- and medium-chain-length (SCL-co-MCL) PHA from xylose by Halomonas. Interestingly, J9UΔxylD-P8xylA was capable of efficiently utilizing glucose and xylose as co-carbon sources for PHA production. Furthermore, fed-batch fermentation of J9UΔxylD-P8xylA coupled to a glucose/xylose co-feeding strategy reached up to 12.57 g/L PHA in a 5-L bioreactor under open and unsterile condition. Utilization of corn straw hydrolysate as the carbon source by J9UΔxylD-P8xylA reached 7.0 g/L cell dry weight (CDW) and 2.45 g/L PHA in an open fermentation. In summary, unsterile production in combination with inexpensive feedstock highlights the potential of the engineered strain for the low-cost production of PHA from lignocellulose-rich agriculture waste.
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Affiliation(s)
- Siqi Wang
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Yujie Liu
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Hongfu Guo
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Yan Meng
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Weini Xiong
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Ruihua Liu
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Chao Yang
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
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Huang M, Zhang H, Ren M, Ji B, Sun K. The synthesis of ectoine enhance the assimilation of ammonia nitrogen in hypersaline wastewater by the salt-tolerant assimilation bacteria sludge. Sci Total Environ 2024; 913:169694. [PMID: 38160842 DOI: 10.1016/j.scitotenv.2023.169694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 12/23/2023] [Accepted: 12/24/2023] [Indexed: 01/03/2024]
Abstract
In contrast to nitrification-denitrification microorganisms that convert ammonia nitrogen in hypersaline wastewater into nitrogen for discharge, this research utilizes sludge enriched with salt-tolerant assimilation bacteria (STAB) to assimilate organic matter and ammonia nitrogen in hypersaline wastewater into ectoine - a biomass with high economic value and resistance to external osmotic pressure. The study investigates the relationship between the synthesis of ectoine and nitrogen removal efficiency of STAB sludge in three sequencing batch reactors (SBR) operated at different salinities (50, 75, and 100 g/L) and organic matter concentrations. The research reveals that, under low concentration carbon sources (TOC/N = 4, NH4+-N = 60 mg/L), the ammonia nitrogen removal efficiency of SBR reactors increased by 14.51 % and 17.25 % within 5 d and 2 d, respectively, when salinity increased from 50 g/L to 75 g/L and 100 g/L. Under high concentration carbon sources (TOC/N = 8, NH4+-N = 60 mg/L), the ammonia nitrogen removal efficiency of STAB sludge in the three reactors stabilized at 80.20 %, 76.71 %, and 72.87 %, and the total nitrogen removal efficiency was finally stabilized at 80.47 %, 73.15 %, and 65.53 %, respectively. The nitrogen removal performance by ammonium-assimilating of STAB sludge is more sustainable under low salinity, while it is more short-term explosive under high salinity. Moreover, the intracellular ectoine concentration of STAB sludge was found to be related to this behavior. Empirical formulas confirm that STAB sludge synthesizes ectoine from nutrients in wastewater through assimilation, and intracellular ectoine has a threshold defect (150 mg/gVss). The ectoine metabolism pathways of STAB sludge was constructed using the Kyoto Encyclopedia of Genes and Genomes (KEGG). The ammonia nitrogen in sewage is converted into glutamic acid under the action of assimilation genes. It then undergoes a tricarboxylic acid cycle to synthesize the crucial precursor of ectoine - aspartic acid. Subsequently, ectoine is produced through ectoine synthase. The findings suggest that when the synthesis of intracellular ectoine reaches saturation, it inhibits the continuous nitrogen removal performance of STAB sludge under high salinity. STAB sludge does not actively release ectoine through channels under stable external osmotic pressure.
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Affiliation(s)
- Minglei Huang
- Zhejiang University, 310013, China; NingboTech University, 315100, China
| | | | - Min Ren
- Ningbo Marine Center, Ministry of Natural Resources, 315100, China
| | - Bixiao Ji
- NingboTech University, 315100, China
| | - Keying Sun
- Zhejiang University, 310013, China; NingboTech University, 315100, China
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Martínez-García E, de Lorenzo V. Pseudomonas putida as a synthetic biology chassis and a metabolic engineering platform. Curr Opin Biotechnol 2024; 85:103025. [PMID: 38061264 DOI: 10.1016/j.copbio.2023.103025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 02/09/2024]
Abstract
The soil bacterium Pseudomonas putida, especially the KT2440 strain, is increasingly being utilized as a host for biotransformations of both industrial and environmental interest. The foundations of such performance include its robust redox metabolism, ability to tolerate a wide range of physicochemical stresses, rapid growth, versatile metabolism, nonpathogenic nature, and the availability of molecular tools for advanced genetic programming. These attributes have been leveraged for hosting engineered pathways for production of valuable chemicals or degradation/valorization of environmental pollutants. This has in turn pushed the boundaries of conventional enzymology toward previously unexplored reactions in nature. Furthermore, modifications to the physical properties of the cells have been made to enhance their catalytic performance. These advancements establish P. putida as bona fide chassis for synthetic biology, on par with more traditional metabolic engineering platforms.
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Affiliation(s)
- Esteban Martínez-García
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Calle Darwin 3, 28049 Madrid, Spain
| | - Víctor de Lorenzo
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Calle Darwin 3, 28049 Madrid, Spain.
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Ren K, Zhao Y, Chen GQ, Ao X, Wu Q. Construction of a Stable Expression System Based on the Endogenous hbpB/ hbpC Toxin-Antitoxin System of Halomonas bluephagenesis. ACS Synth Biol 2024; 13:61-67. [PMID: 38100561 DOI: 10.1021/acssynbio.3c00622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Halomonas bluephagenesis is a halophilic bacterium capable of efficiently producing polyhydroxyalkanoates and other valuable chemicals through high salinity open fermentation, offering an appealing platform for next-generation industrial biotechnology. Various techniques have been developed to engineer Halomonas bluephagenesis, each with its inherent shortcomings. Genome editing methods often entail complex and time-consuming processes, while flexible expression systems relying on plasmids necessitate the use of antibiotics. In this study, we developed a stable recombinant plasmid vector, pHbPBC, based on a novel hbpB/hbpC toxin-antitoxin system found within the endogenous plasmid of Halomonas bluephagenesis. Remarkably, pHbPBC exhibited exceptional stability during 7 days of continuous subculture, eliminating the need for antibiotics or other selection pressures. This stability even rivaled genomic integration, all while achieving higher levels of heterologous expression. Our research introduces a novel approach for genetically modifying and harnessing nonmodel halophilic bacteria, contributing to the advancement of next-generation industrial biotechnology.
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Affiliation(s)
- Kang Ren
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yiqing Zhao
- Beijing No.12 High School, Beijing 100071, China
| | - Guo-Qiang Chen
- Center for Synthetic and Systems Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiang Ao
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiong Wu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Xu T, Mitra R, Tan D, Li Z, Zhou C, Chen T, Xie Z, Han J. Utilization of gene manipulation system for advancing the biotechnological potential of halophiles: A review. Biotechnol Adv 2024; 70:108302. [PMID: 38101552 DOI: 10.1016/j.biotechadv.2023.108302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/02/2023] [Accepted: 12/09/2023] [Indexed: 12/17/2023]
Abstract
Halophiles are salt-loving microorganisms known to have their natural resistance against media contamination even when cultivated in nonsterile and continuous bioprocess system, thus acting as promising cell factories for Next Generation of Industrial Biotechnology (NGIB). NGIB - a successor to the traditional industrial biotechnology, is a more sustainable and efficient bioprocess technology while saving energy and water in a more convenient way as well as reducing the investment cost and skilled workforce requirement. Numerous studies have achieved intriguing outcomes during synthesis of different metabolite using halophiles such as polyhydroxyalkanoates (PHA), ectoine, biosurfactants, and carotenoids. Present-day development in genetic maneuverings have shown optimistic effects on the industrial applications of halophiles. However, viable and competent genetic manipulation system and gene editing tools are critical to accelerate the process of halophile engineering. With the aid of such powerful gene manipulation systems, exclusive microbial chassis are being crafted with desirable features to breed another innovative area of research such as synthetic biology. This review provides an aerial perspective on how the expansion of adaptable gene manipulation toolkits in halophiles are contributing towards biotechnological advancement, and also focusses on their subsequent application for production improvement. This current methodical and comprehensive review will definitely help the scientific fraternity to bridge the gap between challenges and opportunities in halophile engineering.
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Affiliation(s)
- Tong Xu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Ruchira Mitra
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; International College, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Dan Tan
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Zhengjun Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Cheng Zhou
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; College of Biochemical Engineering, Beijing Union University, Beijing 100023, People's Republic of China
| | - Tao Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People's Republic of China
| | - Zhengwei Xie
- Peking University International Cancer Institute, Health Science Center, Peking University, Beijing 100191, People's Republic of China
| | - Jing Han
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
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Wang Z, Li Y, Gao X, Xing J, Wang R, Zhu D, Shen G. Comparative genomic analysis of Halomonas campaniensis wild-type and ultraviolet radiation-mutated strains reveal genomic differences associated with increased ectoine production. Int Microbiol 2023; 26:1009-1020. [PMID: 37067733 PMCID: PMC10622362 DOI: 10.1007/s10123-023-00356-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 04/01/2023] [Accepted: 04/05/2023] [Indexed: 04/18/2023]
Abstract
Ectoine is a natural amino acid derivative and one of the most widely used compatible solutes produced by Halomonas species that affects both cellular growth and osmotic equilibrium. The positive effects of UV mutagenesis on both biomass and ectoine content production in ectoine-producing strains have yet to be reported. In this study, the wild-type H. campaniensis strain XH26 (CCTCCM2019776) was subjected to UV mutagenesis to increase ectoine production. Eight rounds of mutagenesis were used to generate mutated XH26 strains with different UV-irradiation exposure times. Ectoine extract concentrations were then evaluated among all strains using high-performance liquid chromatography analysis, alongside whole genome sequencing with the PacBio RS II platform and comparison of the wild-type strain XH26 and the mutant strain G8-52 genomes. The mutant strain G8-52 (CCTCCM2019777) exhibited the highest cell growth rate and ectoine yields among mutated strains in comparison with strain XH26. Further, ectoine levels in the aforementioned strain significantly increased to 1.51 ± 0.01 g L-1 (0.65 g g-1 of cell dry weight), representing a twofold increase compared to wild-type cells (0.51 ± 0.01 g L-1) when grown in culture medium for ectoine accumulation. Concomitantly, electron microscopy revealed that mutated strain G8-52 cells were obviously shorter than wild-type strain XH26 cells. Moreover, strain G8-52 produced a relatively stable ectoine yield (1.50 g L-1) after 40 days of continuous subculture. Comparative genomics analysis suggested that strain XH26 harbored 24 mutations, including 10 nucleotide insertions, 10 nucleotide deletions, and unique single nucleotide polymorphisms. Notably, the genes orf00723 and orf02403 (lipA) of the wild-type strain mutated to davT and gabD in strain G8-52 that encoded for 4-aminobutyrate-2-oxoglutarate transaminase and NAD-dependent succinate-semialdehyde dehydrogenase, respectively. Consequently, these genes may be involved in increased ectoine yields. These results suggest that continuous multiple rounds of UV mutation represent a successful strategy for increasing ectoine production, and that the mutant strain G8-52 is suitable for large-scale fermentation applications.
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Affiliation(s)
- Zhibo Wang
- 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
| | - Xiang Gao
- 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
| | - Rong Wang
- 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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Zhang J, Yuan Y, Wang Z, Chen T. Metabolic engineering of Halomonas bluephagenesis for high-level mevalonate production from glucose and acetate mixture. Metab Eng 2023; 79:203-213. [PMID: 37657641 DOI: 10.1016/j.ymben.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/14/2023] [Accepted: 08/27/2023] [Indexed: 09/03/2023]
Abstract
Mevalonate (MVA) plays a crucial role as a building block for the biosynthesis of isoprenoids. In this study, we engineered Halomonas bluephagenesis to efficiently produce MVA. Firstly, by screening MVA synthetases from eight different species, the two efficient candidate modules, specifically NADPH-dependent mvaESEfa from Enterococcus faecalis and NADH-dependent mvaESLca from Lactobacillus casei, were integrated into the chromosome, leading to the construction of the H. bluephagenesis MVA11. Through the synergetic utilization of glucose and acetate as mixed carbon sources, MVA11 produced 11.2 g/L MVA with a yield of 0.45 g/g (glucose + acetic acid) in the shake flask. Subsequently, 10 beneficial genes out of 50 targets that could promote MVA production were identified using CRISPR interference. The simultaneous repression of rpoN (encoding RNA polymerase sigma-54 factor) and IldD (encoding L-lactate dehydrogenase) increased MVA titer (13.3 g/L) by 19.23% and yield (0.53 g/g (glucose + acetic acid)) by 17.78%, respectively. Furthermore, introducing the non-oxidative glycolysis (NOG) pathway into MVA11 enhanced MVA yield by 12.20%. Ultimately, by combining these strategies, the resultant H. bluephagenesis MVA13/pli-63 produced 13.9 g/L MVA in the shake flask, and the yield increased to 0.56 g/g (glucose + acetic acid), which was the highest reported so far. Under open fed-batch fermentation conditions, H. bluephagenesis MVA13/pli-63 produced 121 g/L of MVA with a yield of 0.42 g/g (glucose + acetic acid), representing the highest reported titer and yield in the bioreactor to date. This study demonstrates that H. bluephagenesis is one of the most favorable chassis for MVA production.
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Affiliation(s)
- Jing Zhang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin, 300072, China
| | - Yue Yuan
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin, 300072, China
| | - Zhiwen Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin, 300072, China
| | - Tao Chen
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin, 300072, China.
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Zhang W, Liu K, Kong F, Ye T, Wang T. Multiple Functions of Compatible Solute Ectoine and Strategies for Constructing Overproducers for Biobased Production. Mol Biotechnol 2023:10.1007/s12033-023-00827-7. [PMID: 37488320 DOI: 10.1007/s12033-023-00827-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 07/14/2023] [Indexed: 07/26/2023]
Abstract
Ectoine and its derivative 5-hydroxyectoine are compatible solutes initially found in the hyperhalophilic bacterium Ectothiorhodospira halochloris, which inhabits the desert in Egypt. The habitat of ectoine producers implies the primary function of ectoine as a cytoprotectant against harsh conditions such as high salinity, drought, and high radiation. More extensive and in-depth studies have revealed the multiple functions of ectoine in its native producer bacterial cells and other types of cells and its biomolecular components (such as proteins and DNA) as a general protective agent. Its chemical properties as a bio-based amino acid derivative make it attractive for basic scientific research and related industries, such as the food/agricultural industry, cosmetic manufacturing, biologics, and therapeutic agent preparation. This article first discusses the functions and applications of ectoine and 5-hydroxyectoine. Subsequently, more emphasis was placed on advances in bio-based ectoine and/or 5-hydroxyectoine production. Strategies for developing more robust cell factories for highly efficient ectoine and/or 5-hydroxyectoine production are further discussed. We hope this review will provide a valuable reference for studies on the bio-based production of ectoine and 5-hydroxyectoine.
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Affiliation(s)
- Wei Zhang
- College of Life Sciences, Xinyang Normal University, Xinyang, 464000, People's Republic of China
| | - Kun Liu
- College of Biology and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, People's Republic of China
| | - Fang Kong
- College of Biology and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, People's Republic of China
| | - Tao Ye
- College of Biology and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, People's Republic of China
| | - Tianwen Wang
- College of Biology and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, People's Republic of China.
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Benítez-Mateos AI, Paradisi F. Halomonas elongata: a microbial source of highly stable enzymes for applied biotechnology. Appl Microbiol Biotechnol 2023; 107:3183-3190. [PMID: 37052635 PMCID: PMC10160191 DOI: 10.1007/s00253-023-12510-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/14/2023]
Abstract
Extremophilic microorganisms, which are resistant to extreme levels of temperature, salinity, pH, etc., have become popular tools for biotechnological applications. Due to their availability and cost-efficacy, enzymes from extremophiles are getting the attention of researchers and industries in the field of biocatalysis to catalyze diverse chemical reactions in a selective and sustainable manner. In this mini-review, we discuss the advantages of Halomonas elongata as moderate halophilic bacteria to provide suitable enzymes for biotechnology. While enzymes from H. elongata are more resistant to the presence of salt compared to their mesophilic counterparts, they are also easier to produce in heterologous hosts compared with more extremophilic microorganisms. Herein, a set of different enzymes (hydrolases, transferases, and oxidoreductases) from H. elongata are showcased, highlighting their interesting properties as more efficient and sustainable biocatalysts. With this, we aim to improve the visibility of halotolerant enzymes and their uncommon properties to integrate biocatalysis in industrial set-ups. KEYPOINTS: • Production and use of halotolerant enzymes can be easier than strong halophilic ones. • Enzymes from halotolerant organisms are robust catalysts under harsh conditions. • Halomonas elongata has shown a broad enzyme toolbox with biotechnology applications.
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Affiliation(s)
- Ana I Benítez-Mateos
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
| | - Francesca Paradisi
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
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Feng L, Yan J, Jiang Z, Chen X, Li Z, Liu J, Qian X, Liu Z, Liu G, Liu C, Wang Y, Hu G, Dong W, Cui Z. Characterization of polyhydroxybutyrate (PHB) synthesized by newly isolated rare actinomycetes Aquabacterium sp. A7-Y. Int J Biol Macromol 2023; 232:123366. [PMID: 36693609 DOI: 10.1016/j.ijbiomac.2023.123366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023]
Abstract
Polyhydroxyalkanoates (PHAs) as biodegradable plastics have attracted increasing attention due to its biodegradable, biocompatible and renewable advantages. Exploitation some unique microbes for PHAs production is one of the most competitive approaches to meet complex industrial demand, and further develop next-generation industrial biotechnology. In this study, a rare actinomycetes strain A7-Y was isolated and identified from soil as the first PHAs producer of Aquabacterium genus. Produced PHAs by strain A7-Y was identified as poly(3-hydroxybutyrate) (PHB) based on its structure characteristics, which is also similar with commercial PHB. After optimization of fermentation conditions, strain A7-Y can produce 10.2 g/L of PHB in 5 L fed-batch fermenter, corresponding with 54 % PHB content of dry cell weight, which is superior to the reported actinomycetes species. Furthermore, the phaCAB operon in stain A7-Y was excavated to be responsible for the efficient PHB production and verified in recombinant Escherichia coli. Our results indicate that strain A7-Y and its biosynthetic gene cluster are potential candidates for developing a microbial formulation for the PHB production.
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Affiliation(s)
- Li Feng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; College of Life Sciences, Shihezi University, Shihezi 832003, PR China
| | - Jinyuan Yan
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Zhitong Jiang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xue Chen
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Zhoukun Li
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Jiawei Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Xiujuan Qian
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Ziqiang Liu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Guangyu Liu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Chongyu Liu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yuehan Wang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Gang Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China.
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
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