1
|
Yang X, Yang J, Huang H, Yan X, Li X, Lin Z. Achieving robust synthetic tolerance in industrial E. coli through negative auto-regulation of a DsrA-Hfq module. Synth Syst Biotechnol 2024; 9:462-469. [PMID: 38634002 PMCID: PMC11021974 DOI: 10.1016/j.synbio.2024.04.003] [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: 02/05/2024] [Revised: 03/29/2024] [Accepted: 04/06/2024] [Indexed: 04/19/2024] Open
Abstract
In industrial fermentation processes, microorganisms often encounter acid stress, which significantly impact their productivity. This study focused on the acid-resistant module composed of small RNA (sRNA) DsrA and the sRNA chaperone Hfq. Our previous study had shown that this module improved the cell growth of Escherichia coli MG1655 at low pH, but failed to obtain this desired phenotype in industrial strains. Here, we performed a quantitative analysis of DsrA-Hfq module to determine the optimal expression mode. We then assessed the potential of the CymR-based negative auto-regulation (NAR) circuit for industrial application, under different media, strains and pH levels. Growth assay at pH 4.5 revealed that NAR-05D04H circuit was the best acid-resistant circuit to improve the cell growth of E. coli MG1655. This circuit was robust and worked well in the industrial lysine-producing strain E. coli SCEcL3 at a starting pH of 6.8 and without pH control, resulting in a 250 % increase in lysine titer and comparable biomass in shaking flask fermentation compared to the parent strain. This study showed the practical application of NAR circuit in regulating DsrA-Hfq module, effectively and robustly improving the acid tolerance of industrial strains, which provides a new approach for breeding industrial strains with tolerance phenotype.
Collapse
Affiliation(s)
- Xiaofeng Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Jingduan Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Haozheng Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Xiaofang Yan
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Xiaofan Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Zhanglin Lin
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
- School of Biomedicine, Guangdong University of Technology, Guangzhou 510006, China
| |
Collapse
|
2
|
Hu W, Huo X, Bai H, Chen Z, Zhang J, Yang H, Feng S. Insights into the complementation potential of the extreme acidophile's orthologue in replacing Escherichia coli hfq gene-particularly in bacterial resistance to environmental stress. World J Microbiol Biotechnol 2024; 40:105. [PMID: 38386219 DOI: 10.1007/s11274-024-03924-0] [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: 12/17/2023] [Accepted: 02/08/2024] [Indexed: 02/23/2024]
Abstract
Acidithiobacillus caldus is a typical extreme acidophile widely used in the biohydrometallurgical industry, which often experiences extreme environmental stress in its natural habitat. Hfq, an RNA-binding protein, typically functions as a global regulator involved in various cellular physiological processes. Yet, the biological functions of Hfq derived from such extreme acidophile have not been extensively investigated. In this study, the recombinant strain Δhfq/Achfq, constructed by CRISPR/Cas9-mediated chromosome integration, fully or partially restored the phenotypic defects caused by hfq deletion in Escherichia coli, including impaired growth performance, abnormal cell morphology, impaired swarming motility, decreased stress resistance, decreased intracellular ATP and free amino acid levels, and attenuated biofilm formation. Particularly noteworthy, the intracellular ATP level and biofilm production of the recombinant strain were increased by 12.2% and 7.0%, respectively, compared to the Δhfq mutant. Transcriptomic analysis revealed that even under heterologous expression, AcHfq exerted global regulatory effects on multiple cellular processes, including metabolism, environmental signal processing, and motility. Finally, we established a potential working model to illustrate the regulatory mechanism of AcHfq in bacterial resistance to environmental stress.
Collapse
Affiliation(s)
- Wenbo Hu
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China
- School of Life Sciences, Henan Institute of Science and Technology, Xinxiang, Henan, China
| | - Xingyu Huo
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China
| | - Haochen Bai
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China
| | - Zongling Chen
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China
| | - Jianxin Zhang
- College of Fisheries, Henan Normal University, Xinxiang, 453007, People's Republic of China
| | - Hailin Yang
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China
| | - Shoushuai Feng
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China.
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, People's Republic of China.
| |
Collapse
|
3
|
Zhu W, Xi L, Qiao J, Du D, Wang Y, Morigen. Involvement of OxyR and Dps in the repression of replication initiation by DsrA small RNA in Escherichia coli. Gene 2023; 882:147659. [PMID: 37482259 DOI: 10.1016/j.gene.2023.147659] [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: 06/27/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 07/25/2023]
Abstract
Regulation of the cell cycle process is an effective measure to ensure the stability and fidelity of genetic material during the reproduction of bacteria under different stresses. The small RNA DsrA helps bacteria adapt to environments by binding to multiple targets, but its association with the cell cycle remains unclear. Detection by flow cytometry, we first found that the knockout of dsrA promoted replication initiation, and corresponding overexpression of DsrA inhibited replication initiation in Escherichia coli. The absence of the chaperone protein Hfq, the DNA replication negative regulator protein Dps, or the transcription factor OxyR, was found to cause DsrA to no longer inhibit replication initiation. Excess DsrA promotes expression of the oxyR and dps gene, whereas β-galactosidase activity assay showed that deleting oxyR limited the enhancement of dps promoter transcriptional activity by DsrA. OxyR is a known positive regulator of Dps. Our data suggests that the effect of DsrA on replication initiation requires Hfq and that the upregulation of Dps expression by OxyR in response to DsrA levels may be a potential regulatory pathway for the negative regulation of DNA replication initiation.
Collapse
Affiliation(s)
- Weiwei Zhu
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Lingjun Xi
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China
| | - Jiaxin Qiao
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China
| | - Dongdong Du
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China
| | - Yao Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China
| | - Morigen
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China.
| |
Collapse
|
4
|
Mallick S, Das S. Acid-tolerant bacteria and prospects in industrial and environmental applications. Appl Microbiol Biotechnol 2023; 107:3355-3374. [PMID: 37093306 DOI: 10.1007/s00253-023-12529-w] [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: 02/17/2023] [Revised: 04/06/2023] [Accepted: 04/11/2023] [Indexed: 04/25/2023]
Abstract
Acid-tolerant bacteria such as Streptococcus mutans, Acidobacterium capsulatum, Escherichia coli, and Propionibacterium acidipropionici have developed several survival mechanisms to sustain themselves in various acid stress conditions. Some bacteria survive by minor changes in the environmental pH. In contrast, few others adapt different acid tolerance mechanisms, including amino acid decarboxylase acid resistance systems, mainly glutamate-dependent acid resistance (GDAR) and arginine-dependent acid resistance (ADAR) systems. The cellular mechanisms of acid tolerance include cell membrane alteration in Acidithiobacillus thioxidans, proton elimination by F1-F0-ATPase in Streptococcus pyogenes, biofilm formation in Pseudomonas aeruginosa, cytoplasmic urease activity in Streptococcus mutans, synthesis of the protective cloud of ammonia, and protection or repair of macromolecules in Bacillus caldontenax. Apart from cellular mechanisms, there are several acid-tolerant genes such as gadA, gadB, adiA, adiC, cadA, cadB, cadC, speF, and potE that help the bacteria to tolerate the acidic environment. This acid tolerance behavior provides new and broad prospects for different industrial applications and the bioremediation of environmental pollutants. The development of engineered strains with acid-tolerant genes may improve the efficiency of the transgenic bacteria in the treatment of acidic industrial effluents. KEY POINTS: • Bacteria tolerate the acidic stress by methylating unsaturated phospholipid tail • The activity of decarboxylase systems for acid tolerance depends on pH • Genetic manipulation of acid-tolerant genes improves acid tolerance by the bacteria.
Collapse
Affiliation(s)
- Souradip Mallick
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
| |
Collapse
|
5
|
Jiang Z, Lu J, Tong Y, Yang H, Feng S. Enhancement of acid tolerance of Escherichia coli by introduction of molecule chaperone CbpA from extremophile. World J Microbiol Biotechnol 2023; 39:158. [PMID: 37046107 DOI: 10.1007/s11274-023-03613-4] [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: 02/24/2023] [Accepted: 04/08/2023] [Indexed: 04/14/2023]
Abstract
Molecular chaperone CbpA from extreme acidophile Acidithiobacillus caldus was applied to improve acid tolerance of Escherichia coli via CRISPR/Cas9. Cell growth and viability of plasmid complementary strain indicated the importance of cbpAAc for bacteria acid tolerance. With in situ gene replacement by CRISPR/Cas9 system, colony formation unit (CFU) of genome recombinant strain BL21-ΔcbpA/AccbpA showed 7.7 times higher cell viability than deficient strain BL21-ΔcbpA and 2.3 times higher than wild type. Cell morphology observation using Field Emission Scanning Electron Microscopy (FESEM) revealed cell breakage of BL21-ΔcbpA and significant recovery of BL21-ΔcbpA/AccbpA. The intracellular ATP level of all strains gradually decreased along with the increased stress time. Particularly, the value of recombinant strain was 56.0% lower than that of deficient strain after 5 h, indicating that the recombinant strain consumed a lot of energy to resist acid stress. The arginine concentration in BL21-ΔcbpA/AccbpA was double that of BL21-ΔcbpA, while the aspartate and glutamate contents were 14.8% and 6.2% higher, respectively, compared to that of wild type. Moreover, RNA-Seq analysis examined 93 genes down-regulated in BL21-ΔcbpA compared to wild type strain, while 123 genes were up-regulated in BL21-ΔcbpA/AccbpA compared to BL21-ΔcbpA, with an emphasis on energy metabolism, transport, and cell components. Finally, the working model in response to acid stress of cbpA from A. caldus was developed. This study constructed a recombinant strain resistant to acid stress and also provided a reference for enhancing microorganisms' robustness to various conditions.
Collapse
Affiliation(s)
- Zhenming Jiang
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Jie Lu
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Yanjun Tong
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, China
| | - Hailin Yang
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Shoushuai Feng
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China.
| |
Collapse
|
6
|
Hu W, Tong Y, Liu J, Chen P, Yang H, Feng S. Improving acid resistance of Escherichia coli base on the CfaS-mediated membrane engineering strategy derived from extreme acidophile. Front Bioeng Biotechnol 2023; 11:1158931. [PMID: 37025359 PMCID: PMC10070827 DOI: 10.3389/fbioe.2023.1158931] [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: 02/04/2023] [Accepted: 03/08/2023] [Indexed: 04/08/2023] Open
Abstract
Industrial microorganisms used for the production of organic acids often face challenges such as inhibited cell growth and reduced production efficiency due to the accumulation of acidic metabolites. One promising way for improving the acid resistance of microbial cells is to reconstruct their membranes. Herein, the overexpression of cfa2 from extreme acidophile endowed E. coli with high-performance on resistance to the acid stress. The engineered strain M1-93-Accfa2, constructed by CRISPR/Cas9-mediated chromosome integration, also exhibited a significantly higher resistance to severe acid stress. The analysis of fatty acid profiles indicated that the proportion of Cy-19:0 in the cell membrane of M1-93-Accfa2 increased by 5.26 times compared with the control, while the proportion of C18:1w9c decreased by 5.81 times. Correspondingly, the permeability and fluidity of the membrane decreased significantly. HPLC analysis demonstrated that the contents of intracellular glutamic acid, arginine, methionine and aspartic acid of M1-93-Accfa2 were 2.59, 2.04, 22.07 and 2.65 times that of the control after environmental acidification, respectively. Meanwhile, transmission electron microscopy observation indicated that M1-93-Accfa2 could maintain a plumper cell morphology after acid stimulation. M1-93-Accfa2 also exhibited higher-performance on the resistance to organic acids, especially succinic acid stress. These results together demonstrated the great potential of M1-93-Accfa2 constructed here in the production of organic acids.
Collapse
Affiliation(s)
- Wenbo Hu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yanjun Tong
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Junjie Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Panyan Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology (Jiangnan University) Ministry of Education, Jiangnan University, Wuxi, China
| | - Hailin Yang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology (Jiangnan University) Ministry of Education, Jiangnan University, Wuxi, China
- *Correspondence: Hailin Yang, ; Shoushuai Feng,
| | - Shoushuai Feng
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology (Jiangnan University) Ministry of Education, Jiangnan University, Wuxi, China
- *Correspondence: Hailin Yang, ; Shoushuai Feng,
| |
Collapse
|
7
|
Wu N, Xing M, Chen Y, Zhang C, Li Y, Song P, Xu Q, Liu H, Huang H. Improving the productivity of malic acid by alleviating oxidative stress during Aspergillus niger fermentation. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:151. [PMID: 36581946 PMCID: PMC9801644 DOI: 10.1186/s13068-022-02250-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 12/15/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND As an attractive platform chemical, malic acid has been commonly used in the food, feed and pharmaceutical field. Microbial fermentation of biobased sources to produce malic acid has attracted great attention because it is sustainable and environment-friendly. However, most studies mainly focus on improving yield and ignore shortening fermentation time. A long fermentation period means high cost, and hinders the industrial applications of microbial fermentation. Stresses, especially oxidative stress generated during fermentation, inhibit microbial growth and production, and prolong fermentation period. Previous studies have shown that polypeptides could effectively relieve stresses, but the underlying mechanisms were poorly understood. RESULTS In this study, polypeptides (especially elastin peptide) addition improves the productivity of malic acid in A. niger, resulting in shortening of fermentation time from 120 to 108 h. Transcriptome and biochemical analyses demonstrated that both antioxidant enzyme-mediated oxidative stress defense system, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and nonenzymatic antioxidant system, such as glutathione, were enhanced in the presence of elastin peptide, suggesting elastin peptide relieving oxidative stresses is involved in many pathways. In order to further investigate the relationship between oxidative stress defense and malic acid productivity, we overexpressed three enzymes (Sod1, CAT, Tps1) related to oxidation resistance in A. niger, respectively, and these resulting strains display varying degree of improvement in malic acid productivity. Especially, the strain overexpressing the Sod1 gene achieved a malate titer of 91.85 ± 2.58 g/L in 96 h, corresponding to a productivity of 0.96 g/L/h, which performs better than elastin peptide addition. CONCLUSIONS Our investigation provides an excellent reference for alleviating the stress of the fungal fermentation process and improving fermentation efficiency.
Collapse
Affiliation(s)
- Na Wu
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China ,grid.260474.30000 0001 0089 5711College of Life Sciences, Nanjing Normal University, Nanjing, 210046 China
| | - Mingyan Xing
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China
| | - Yaru Chen
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China
| | - Chi Zhang
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China
| | - Yingfeng Li
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China ,grid.260474.30000 0001 0089 5711College of Life Sciences, Nanjing Normal University, Nanjing, 210046 China
| | - Ping Song
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China
| | - Qing Xu
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China
| | - Hao Liu
- grid.413109.e0000 0000 9735 6249Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, Tianjin, 300457 China
| | - He Huang
- grid.260474.30000 0001 0089 5711School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023 China ,grid.412022.70000 0000 9389 5210College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| |
Collapse
|
8
|
Sun Q, Gao S, Yu S, Zheng P, Zhou J. Production of (2S)-sakuranetin from (2S)-naringenin in Escherichia coli by strengthening methylation process and cell resistance. Synth Syst Biotechnol 2022; 7:1117-1125. [PMID: 36017331 PMCID: PMC9399173 DOI: 10.1016/j.synbio.2022.07.004] [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] [Received: 05/18/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/15/2022] Open
Abstract
(2S)-Sakuranetin is a 7-O-methylflavonoid that has anticancer, antiviral, and antimicrobial activities. Methylation process is involved in biosynthesizing (2S)-sakuranetin from (2S)-naringenin, in which S-adenosylmethionine (SAM) serves as the methyl donor. In this study, after methyl donor and substrate inhibition were identified as limiting factors for (2S)-sakuranetin biosynthesis, an efficient (2S)-sakuranetin-producing strain was constructed by enhancing methyl donor supply and cell tolerance to (2S)-naringenin. Firstly, PfOMT3 from Perilla frutescens was selected as the optimal flavonoid 7-O-methyltransferase (F7-OMT) for the conversion of (2S)-naringenin to (2S)-sakuranetin. Then, the methylation process was upregulated by regulating pyridoxal 5′-phosphate (PLP) content, key enzymes in methionine synthesis pathway, and the availability of ATP. Furthermore, genes that can enhance cell resistance to (2S)-naringenin were identified from molecular chaperones and sRNAs. Finally, by optimizing the fermentation process, 681.44 mg/L of (2S)-sakuranetin was obtained in 250-mL shake flasks. The titer of (2S)-sakuranetin reached 2642.38 mg/L in a 5-L bioreactor, which is the highest titer ever reported. This work demonstrates the importance of cofactor PLP in methylation process, and provides insights to biosynthesize other O-methylated flavonoids efficiently in E. coli.
Collapse
Affiliation(s)
- Qiumeng Sun
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Song Gao
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Shiqin Yu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Pu Zheng
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Corresponding author. School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.
| | - Jingwen Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Corresponding author. Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.
| |
Collapse
|
9
|
Liu G, Chang H, Qiao Y, Huang K, Zhang A, Zhao Y, Feng Z. Profiles of Small Regulatory RNAs at Different Growth Phases of Streptococcus thermophilus During pH-Controlled Batch Fermentation. Front Microbiol 2021; 12:765144. [PMID: 35035386 PMCID: PMC8753986 DOI: 10.3389/fmicb.2021.765144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/05/2021] [Indexed: 12/02/2022] Open
Abstract
Small regulatory RNA (sRNA) has been shown to play an important role under various stress conditions in bacteria, and it plays a vital role in regulating growth, adaptation and survival through posttranscriptional control of gene expression in bacterial cells. Streptococcus thermophilus is widely used as a starter culture in the manufacture of fermented dairy products. However, the lack of reliable information on the expression profiles and potential physiological functions of sRNAs in this species hinders our understanding of the importance of sRNAs in S. thermophilus. The present study was conducted to assess the expression profiles of sRNAs in S. thermophilus and to identify sRNAs that exhibited significant changes. A total of 530 potential sRNAs were identified, including 198 asRNAs, 135 sRNAs from intergenic regions, and 197 sRNAs from untranslated regions (UTRs). Significant changes occurred in the expression of 238, 83, 194, and 139 sRNA genes during the lag, early exponential growth, late exponential growth, and stationary phases, respectively. The expression of 14 of the identified sRNAs was verified by qRT-PCR. Predictions of the target genes of these candidate sRNAs showed that the primary metabolic pathways targeted were involved in carbon metabolism, biosynthesis of amino acids, ABC transporters, the metabolism of amino and nucleotide sugars, purine metabolism, and the phosphotransferase system. The expression of the predicted target genes was further analyzed to better understand the roles of sRNAs during different growth stages. The results suggested that these sRNAs play crucial roles by regulating biological pathways during different growth phases of S. thermophilus. According to the results, sRNAs sts141, sts392, sts318, and sts014 are involved in the regulation of osmotic stress. sRNAs sts508, sts087, sts372, sts141, sts375, and sts119 are involved in the regulation of starvation stress. sRNAs sts129, sts226, sts166, sts231, sts204, sts145, and sts236 are involved in arginine synthesis. sRNAs sts033, sts341, sts492, sts140, sts230, sts172, and sts377 are involved in the ADI pathway. The present study provided valuable information for the functional study of sRNAs in S. thermophilus and indicated a future research direction for sRNA in S. thermophilus. Overall, our results provided new insights for understanding the complex regulatory network of sRNAs in S. thermophilus.
Collapse
Affiliation(s)
- Gefei Liu
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Haode Chang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Yali Qiao
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Kai Huang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Ao Zhang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
| | - Yu Zhao
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning, 571533, Hainan, China
- Yu Zhao,
| | - Zhen Feng
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, 600 Chanjiang Road,150030, Harbin, Heilongjiang, China
- College of Food and Biological Engineering, Qiqihar University, 42 Wenhua Road, 160006, Qiqihar, China
- *Correspondence: Zhen Feng,
| |
Collapse
|
10
|
Current Progress in Production of Building-Block Organic Acids by Consolidated Bioprocessing of Lignocellulose. FERMENTATION-BASEL 2021. [DOI: 10.3390/fermentation7040248] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Several organic acids have been indicated among the top value chemicals from biomass. Lignocellulose is among the most attractive feedstocks for biorefining processes owing to its high abundance and low cost. However, its highly complex nature and recalcitrance to biodegradation hinder development of cost-competitive fermentation processes. Here, current progress in development of single-pot fermentation (i.e., consolidated bioprocessing, CBP) of lignocellulosic biomass to high value organic acids will be examined, based on the potential of this approach to dramatically reduce process costs. Different strategies for CBP development will be considered such as: (i) design of microbial consortia consisting of (hemi)cellulolytic and valuable-compound producing strains; (ii) engineering of microorganisms that combine biomass-degrading and high-value compound-producing properties in a single strain. The present review will mainly focus on production of organic acids with application as building block chemicals (e.g., adipic, cis,cis-muconic, fumaric, itaconic, lactic, malic, and succinic acid) since polymer synthesis constitutes the largest sector in the chemical industry. Current research advances will be illustrated together with challenges and perspectives for future investigations. In addition, attention will be dedicated to development of acid tolerant microorganisms, an essential feature for improving titer and productivity of fermentative production of acids.
Collapse
|