Article
Microbiology
Reina Deol, Ashweetha Louis, Harper Lee Glazer, Warren Hosseinion, Anna Bagley, Pete Chandrangsu
Summary: Zinc and copper are essential micronutrients that are toxic to bacteria at elevated concentrations. Bacteria have evolved defense mechanisms, including the production of extracellular polymeric substance poly-gamma-glutamate (gamma-PGA) to combat zinc and copper excess. This study provides new insight into metal resistance mechanisms and regulation of bacterial gamma-PGA biosynthesis.
MICROBIOLOGY SPECTRUM
(2022)
Article
Agriculture, Multidisciplinary
Shengbao Chen, Jiaming Fu, Bo Yu, Limin Wang
Summary: In this study, a genetic operating system was developed to enable the production of ?-PGA with diverse molecular masses. The system was demonstrated to successfully produce ?-PGA with specific M (w) values, providing a research basis for sustainable production of desirable ?-PGA.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2023)
Article
Biochemical Research Methods
Liu-xiu Hu, Ming Zhao, Wen-song Hu, Meng-jie Zhou, Jun-bao Huang, Xi-lin Huang, Xu-li Gao, Ya-ni Luo, Chuang Li, Kun Liu, Zheng-lian Xue, Yan Liu
Summary: As a natural biological macromolecule, gamma-polyglutamic acid (gamma-PGA) plays a significant role in medicine, food, and cosmetic industries due to its unique properties. Current methods for increasing gamma-PGA yield are not effective due to the viscosity issue. This study successfully improved the yield of gamma-PGA by using a dynamic regulation strategy based on quorum sensing.
ACS SYNTHETIC BIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Jing Li, Shengbao Chen, Jiaming Fu, Jianchun Xie, Jiansong Ju, Bo Yu, Limin Wang
Summary: This study demonstrated the potential application of B. subtilis 242 for cost-effective production of low-Mw-gamma-PGA from cane molasses.
MICROBIAL CELL FACTORIES
(2022)
Article
Biotechnology & Applied Microbiology
Lifei Guo, Liang Lu, Huichao Wang, Xiaoxing Zhang, Genan Wang, Tingbin Zhao, Guobao Zheng, Changsheng Qiao
Summary: This study found that the addition of FeSO4•7H(2)O in sugarcane molasses can increase the yield of γ-PGA and cell growth. Further investigation revealed that this additive can enhance the abundance of intracellular metabolites and upregulate the glycolysis pathway and TCA cycle.
MICROBIAL CELL FACTORIES
(2023)
Review
Biotechnology & Applied Microbiology
Zheng Zhang, Penghui He, Dongbo Cai, Shouwen Chen
Summary: This review focuses on the genetic and metabolic engineering of microorganisms for gamma-PGA production, including strategies to enhance raw materials utilization, precursor supply, gamma-PGA synthetase gene cluster, transcription regulation, cofactor regeneration, energy engineering, and blocking synthetic pathways of by-products. The expression of gamma-PGA synthetase, glutamate racemase, and gamma-PGA hydrolase were manipulated to obtain gamma-PGA with different configurations and molecular weights. The review also discusses the metabolic engineering of other hosts for high-level production of gamma-PGA.
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
(2022)
Article
Agronomy
Lei Zhang, Lingli Wang, Yu Sun, Xiaoyan Dong, Zhanbo Wei, Lili Zhang, Yuanliang Shi
Summary: Poly-gamma-glutamic acid (gamma-PGA) significantly improves root morphological traits and enhances the uptake of nitrogen by crops. The response of root morphology to gamma-PGA varies depending on the type of fertilizer used. Gamma-PGA promotes root growth when applied with CO(NH2)2, but inhibits it when applied with (NH4)2SO4 due to high ammonium content in the soil.
Article
Food Science & Technology
Han Hu, Caiyun Wu, Fanglan Ge, Yao Ren, Wei Li, Jiao Li
Summary: In this study, a glutamic acid-independent poly gamma-glutamic acid (gamma-PGA) producing Bacillus velezensis SCP024-S-4 bacterial strain was isolated and used for solid fermentation of soybean meal (SBM), resulting in improved nutritional quality. The maximum yield of gamma-PGA in fermented soybean meal (FSBM) reached 89.64 g/kg without adding glutamic acid. Furthermore, FSBM showed increased protein, free amino acid, and small peptide content, while decreasing soy globulin, 8-conglutinin, and trypsin inhibitor levels. Mouse experiments demonstrated that FSBM promoted weight growth rate without negative effects on blood and spleen. Additionally, FSBM increased the richness of intestinal microbiota, particularly Lactobacillus species. This study offers a feasible strategy to enhance the nutritional quality of SBM as an animal feed.
Article
Biochemistry & Molecular Biology
Yin Guo, Yuanyuan Liu, Zejian Yang, Guiguang Chen, Zhiqun Liang, Wei Zeng
Summary: In this study, the production of poly-?-glutamic acid (PGA) by Bacillus subtilis was investigated using stage-controlled fermentation and viscosity reduction strategy. Different factors such as temperature, pH, aeration rate, and agitation speed were optimized for the two-stage controlled fermentation. Results showed that the PGA titer did not significantly increase compared to non-stage controlled fermentation, which may be due to the high viscosity and low dissolved oxygen of the fermentation broth. Therefore, a viscosity reduction strategy was developed to further improve the production of PGA, resulting in an increase of PGA titer by 17.66% to 32.94% compared to non-stage controlled fermentation. This study provides valuable insights for process control strategies in high-viscosity fermentation systems.
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
(2023)
Article
Food Science & Technology
Yuji Kubo, Masuko Kobori, Rikio Nakagawa, Takanori Yoshiura, Toshiyuki Asano, Ayanobu Takeda, Tomotsugu Noguchi
Summary: A high-accuracy method for quantifying gamma-PGA content in natto was developed, showing high repeatability and accuracy. The method effectively removes protein and peptide contaminants and is applicable to both gamma-PGA-rich and gamma-PGA-poor natto samples.
FOOD SCIENCE AND TECHNOLOGY RESEARCH
(2021)
Review
Food Science & Technology
Danfeng Li, Lizhen Hou, Yaxin Gao, Zhiliang Tian, Bei Fan, Fengzhong Wang, Shuying Li
Summary: This article provides a comprehensive overview of the production, biosynthetic pathway, and metabolic regulation of gamma-PGA. By studying the factors that influence its synthesis, it is possible to improve the yield and productivity of γ-PGA and promote its industrial application.
Article
Microbiology
Jian Xue, Tong Tong, Rui Wang, Yibin Qiu, Yian Gu, Liang Sun, Hong Xu, Peng Lei
Summary: The study reveals that gamma-PGA promotes biofilm formation and colonization of Bacillus atrophaeus NX-12, enhancing its biocontrol capability.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Dexin Wang, Xiaoping Fu, Dasen Zhou, Jiaqi Gao, Wenqin Bai
Summary: In this study, a novel gamma-PGA-producing strain Bacillus tequilensis BL01 was isolated, and genetic engineering strategies were implemented to improve gamma-PGA production. Compared with the wild type strain, the engineered strain showed a 2.17-fold and 1.32-fold increase in gamma-PGA production in flask and fermenter, respectively. Different molecular weights of gamma-PGA were successfully obtained, expanding its industrial applications.
MICROBIAL CELL FACTORIES
(2022)
Article
Soil Science
Lei Zhang, Jichao Gao, Lingli Wang, Yu Sun, Xiaoyan Dong, Jiubo Pei, Zhanbo Wei, Lili Zhang, Yuanliang Shi
Summary: Poly-gamma-glutamic acid (gamma-PGA), as a fertilizer synergist, has a significant promotional effect on nitrogen (N) fertilizer efficiency and crop production by regulating N transformation in soil. However, the underlying mechanism of its effect on soil N cycling is not well understood.
APPLIED SOIL ECOLOGY
(2023)
Article
Biotechnology & Applied Microbiology
Sergio Andres Cristiano-Fajardo, Daniela Barron-Reyes, Celia Flores, Agustin Luna-Bulbarela, Esmeralda Soriano-Pena, Raunel Tinoco-Valencia, Enrique Galindo, Leobardo Serrano-Carreon
Summary: This study investigated the influence of acidic growing conditions and glucose specific uptake rate on growth, quorum sensing-related metabolites production, and sporulation of Bacillus velezensis 83. The findings suggest that spore production of B. velezensis 83 is dependent on pH conditions, with bacterial growth occurring at pH 5 and sporulation at pH 6.8. The study also revealed that glucose availability and the Rap-Phr system may play a role in regulating sporulation.
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
(2023)
