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Wei X, Yang L, Chen Z, Xia W, Chen Y, Cao M, He N. Molecular weight control of poly-γ-glutamic acid reveals novel insights into extracellular polymeric substance synthesis in Bacillus licheniformis. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:60. [PMID: 38711141 DOI: 10.1186/s13068-024-02501-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/04/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from Bacillus species. The function of γ-PGA varies with its molecular weight (Mw). RESULTS Herein, different endogenous promoters in Bacillus licheniformis were selected to regulate the expression levels of pgdS, resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 103 to 2.03 × 104 kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the pgdS engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the pgdS engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield. CONCLUSIONS Here, we present a novel insight that increased pgdS expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in B. licheniformis and provided an effective strategy for the controlled synthesis of extracellular polymeric substances.
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Affiliation(s)
- Xiaoyu Wei
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Lijie Yang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Zhen Chen
- College of Life Science, Xinyang Normal University, Xinyang, 464000, China.
| | - Wenhao Xia
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Yongbin Chen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China.
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China.
| | - Ning He
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China.
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China.
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Zeng W, Liu Y, Shu L, Guo Y, Wang L, Liang Z. Production of ultra-high-molecular-weight poly-γ-glutamic acid by a newly isolated Bacillus subtilis strain and genomic and transcriptomic analyses. Biotechnol J 2024; 19:e2300614. [PMID: 38581093 DOI: 10.1002/biot.202300614] [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: 11/09/2023] [Revised: 03/01/2024] [Accepted: 03/14/2024] [Indexed: 04/08/2024]
Abstract
Poly-γ-glutamic acid (γ-PGA) is a microbial-derived polymer with molecular weight (Mw) from 104 to 107 Da, and the high-Mw (> 7.0 × 105 Da) or ultra-high-Mw (> 5.0 × 106 Da) γ-PGA has important application value as a tissue engineering material, as a flocculant, and as a heavy metal remover. Therefore, how to produce these high-Mw γ-PGAs with low cost and high efficiency has attracted wide attention. In this study, a γ-PGA producer was isolated from the natural environment, and identified and named Bacillus subtilis GXD-20. Then, the ultra-high-Mw (> 6.0 × 106 Da) γ-PGA produced by GXD-20 was characterized. Interestingly, GXD-20 could produce γ-PGA at 42°C, and exhibited a γ-PGA titer of up to 22.29 ± 0.59 g L-1 in a 5-L fermenter after optimization of the fermentation process. Comparative genomic analysis indicated that the specific protein sequence and subcellular localization of PgdS (a γ-PGA-degrading enzyme) were closely related to the ultra-high-Mw of γ-PGA. Transcriptomic analysis revealed that the high γ-PGA titer at 42°C was mainly related to the high expression of genes encoding enzymes for sucrose transportation and utilization, nitrogen transportation, endogenous glutamate synthesis, and γ-PGA synthesis. These results provide new insights into the production of ultra-high-Mw γ-PGA by Bacillus at high temperatures.
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Affiliation(s)
- Wei Zeng
- Key Laboratory of Biochemistry and Molecular Biology (Guilin Medical University), Education Department of Guangxi Zhuang Autonomous Region, School of Intelligent Medicine and Biotechnology, Guilin Medical University, Guilin, Guangxi, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enzyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Yuanyuan Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enzyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Lin Shu
- Key Laboratory of Biochemistry and Molecular Biology (Guilin Medical University), Education Department of Guangxi Zhuang Autonomous Region, School of Intelligent Medicine and Biotechnology, Guilin Medical University, Guilin, Guangxi, China
| | - Yin Guo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enzyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Linye Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enzyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Zhiqun Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enzyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
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Wang Y, Wang L, Hu Y, Qin J, Yu B. Design and optimization of ε-poly-l-lysine with specific functions for diverse applications. Int J Biol Macromol 2024; 262:129513. [PMID: 38262828 DOI: 10.1016/j.ijbiomac.2024.129513] [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: 11/01/2023] [Revised: 01/03/2024] [Accepted: 01/13/2024] [Indexed: 01/25/2024]
Abstract
ε-Poly-l-lysine (ε-PL) is a natural homo-poly(amino acid) which can be produced by microorganisms. With the advantages in broad-spectrum antimicrobial activity, biodegradability, and biocompatibility, ε-PL has been widely used as a preservative in the food industry. Different molecular architectures endow ε-PL and ε-PL-based materials with versatile applications. However, the microbial synthesis of ε-PL is currently limited by low efficiencies in genetic engineering and molecular architecture modification. This review presents recent advances in ε-PL production and molecular architecture modification of microbial ε-PL, with a focus on the current challenges and solutions for the improvement of the productivity and diversity of ε-PL. In addition, we highlight recent examples where ε-PL has been applied to expand the versability of edible films and nanoparticles in various applications. Commercial production and the challenges and future research directions in ε-PL biosynthesis are also discussed. Currently, although the main use of ε-PL is as a food preservative, ε-PL and ε-PL-based polymers have shown excellent application potential in biomedical fields. With the development of synthetic biology, the design and synthesis of ε-PL with a customized molecular architecture are possible in the near future. ε-PL-based polymers with specific functions will be a new trend in biopolymer manufacturing.
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Affiliation(s)
- Yi Wang
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Limin Wang
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Yangfan Hu
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jiayang Qin
- College of Pharmacy, Binzhou Medical University, Yantai 264003, China.
| | - Bo Yu
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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Qian J, Wang Y, Hu Z, Shi T, Wang Y, Ye C, Huang H. Bacillus sp. as a microbial cell factory: Advancements and future prospects. Biotechnol Adv 2023; 69:108278. [PMID: 37898328 DOI: 10.1016/j.biotechadv.2023.108278] [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: 07/07/2023] [Revised: 09/27/2023] [Accepted: 10/25/2023] [Indexed: 10/30/2023]
Abstract
Bacillus sp. is one of the most distinctive gram-positive bacteria, able to grow efficiently using cheap carbon sources and secrete a variety of useful substances, which are widely used in food, pharmaceutical, agricultural and environmental industries. At the same time, Bacillus sp. is also recognized as a safe genus with a relatively clear genetic background, which is conducive to the industrial production of target metabolites. In this review, we discuss the reasons why Bacillus sp. has been so extensively studied and summarize its advances in systems and synthetic biology, engineering strategies to improve microbial cell properties, and industrial applications in several metabolic engineering applications. Finally, we present the current challenges and possible solutions to provide a reliable basis for Bacillus sp. as a microbial cell factory.
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Affiliation(s)
- Jinyi Qian
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China
| | - Yuzhou Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China
| | - Zijian Hu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China
| | - Tianqiong Shi
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China.
| | - Yuetong Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China.
| | - Chao Ye
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China.
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, PR China.
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