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He F, Gao B, Cheng X, Zhai J, Zhang X, Yang C, Jiewei T. High-level production of poly-γ-glutamic acid by a newly isolated Bacillus sp. YJY-8 and potential use in increasing the production of tomato. Prep Biochem Biotechnol 2024; 54:637-646. [PMID: 37768129 DOI: 10.1080/10826068.2023.2261058] [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] [Indexed: 09/29/2023]
Abstract
Strain YJY-8, a new γ-polyglutamic acid producer, was separated from fermented soybean paste samples. The strain was identified as a genus of Bacillus by morphological and 16S rDNA sequence analysis and was named Bacillus sp. YJY-8. The optimal medium composition and cultural conditions were studied using a single-factor experiment and a response surface experiment. The optimized medium consisted of monosodium glutamate 70 g/L, glucose 54.3 g/L, glycerol 31.8 g/L, ammonium sulfate 11.1 g/L, yeast extract 3.2 g/L, tryptone 1.5 g/L, L-glutamic acid 6.8 g/L, MgSO4 7H2O 0.5 g/L, FeCl3 6H2O 0.02 g/L, KH2PO4 0.9 g/L, CaCl2 0.03 g/L, MnSO4 H2O 0.3 g/L, ammonium molybdate 0.02 g/L, pH 7.0. The optimal cultivation conditions were 35 °C and pH 7.0. Under the optimized conditions, after 48 hr of cultivation, the highest shaking flask fermentation level of γ-PGA reached 65.2 ± 0.36 g/L. In addition, through fed-batch fermentation in 30 L fermenters, the fermentation level of γ-PGA reached its highest level at 88.42 g/L and productivity was 1.23 g/(L hr) after 72 hr. Then, the effect of γ-PGA on tomato yield was investigated. At the seedling stage, the plant height and stem diameter of γ-PGA treated plants increased by 5.69 and 15.735% after spraying γ-PGA for 19 days. During the flowering and fruiting period, the stem diameter of the γ-PGA treatment group increased by 6.74%, with a maximum increase of 11.65%. The number of fruit branches increased by 0.56-16.29% and the number of fruit sets increased by 1.01-28.47%. At the fruit maturation stage, the yield of tomatoes increased by 10.51, 14.27, and 5.83%.
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Affiliation(s)
- Fuming He
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
| | - Baojun Gao
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
| | - Xin Cheng
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
| | - Jiao Zhai
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
| | - Xinqing Zhang
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
| | - Chuanlun Yang
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
| | - Tian Jiewei
- Chambroad Chemical Industry Research Institute Co., Ltd, Binzhou, P.R. China
- Shan Dong Chambroad Holding Group Co., Ltd, Binzhou, P.R. China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu, P.R. 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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Effects of Fe 2+ addition to sugarcane molasses on poly-γ-glutamic acid production in Bacillus licheniformis CGMCC NO. 23967. Microb Cell Fact 2023; 22:37. [PMID: 36829191 PMCID: PMC9960700 DOI: 10.1186/s12934-023-02042-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 02/12/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Poly-γ-glutamic acid (γ-PGA) is biodegradable, water-soluble, environment-friendly, and edible. Consequently, it has a variety of industrial applications. It is crucial to control production cost and increase output for industrial production γ-PGA. RESULTS Here γ-PGA production from sugarcane molasses by Bacillus licheniformis CGMCC NO. 23967 was studied in shake-flasks and bioreactors, the results indicate that the yield of γ-PGA could reach 40.668 g/L in a 5L stirred tank fermenter. Further study found that γ-PGA production reached 70.436 g/L, γ-PGA production and cell growth increased by 73.20% and 55.44%, respectively, after FeSO4·7H2O was added. Therefore, we investigated the metabolomic and transcriptomic changes following FeSO4·7H2O addition. This addition resulted in increased abundance of intracellular metabolites, including amino acids, organic acids, and key TCA cycle intermediates, as well as upregulation of the glycolysis pathway and TCA cycle. CONCLUSIONS These results compare favorably with those obtained from glucose and other forms of biomass feedstock, confirming that sugarcane molasses can be used as an economical substrate without any pretreatment. The addition of FeSO4·7H2O to sugarcane molasses may increase the efficiency of γ-PGA production in intracellular.
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Zhang Z, He P, Cai D, Chen S. Genetic and metabolic engineering for poly-γ-glutamic acid production: current progress, challenges, and prospects. World J Microbiol Biotechnol 2022; 38:208. [DOI: 10.1007/s11274-022-03390-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/13/2022] [Indexed: 11/29/2022]
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Zhang Q, Chen Y, Gao L, Chen J, Ma X, Cai D, Wang D, Chen S. Enhanced production of poly-γ-glutamic acid via optimizing the expression cassette of Vitreoscilla hemoglobin in Bacillus licheniformis. Synth Syst Biotechnol 2022; 7:567-573. [PMID: 35155838 PMCID: PMC8801620 DOI: 10.1016/j.synbio.2022.01.006] [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: 11/12/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 01/16/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is a natural polymer with various applications, and its high-viscosity hinders oxygen transmission and improvement of synthesis level. Vitreoscilla hemoglobin (VHB) has been introduced into various hosts as oxygen carrier, however, its expression strength and contact efficiency with oxygen hindered efficient oxygen transfer and metabolite synthesis. Here, we want to optimize the expression cassette of VHB for γ-PGA production. Firstly, our results implied that γ-PGA yields were enhanced when introducing twin-arginine translocation (Tat) signal peptides (SPYwbN, SPPhoD and SPTorA) into VHB expression cassette, and the best performance was attained by SPYwbN from Bacillus subtilis, the γ-PGA yield of which was 18.53% higher than that of control strain, and intracellular ATP content and oxygen transfer coefficient (KLa) were increased by 29.71% and 73.12%, respectively, indicating that VHB mediated by SPYwbN benefited oxygen transfer and ATP generation for γ-PGA synthesis. Furthermore, four promoters were screened, and Pvgb was proven as the more suitable promoter for VHB expression and γ-PGA synthesis, and γ-PGA yield of attaining strain WX/pPvgb-YwbN-Vgb was further increased to 40.59 g/L by 10.18%. Finally, WX/pPvgb-YwbN-Vgb was cultivated in 3 L fermentor for fed-batch fermentation, and 46.39 g/L γ-PGA was attained by glucose feeding, increased by 49.26% compared with the initial yield (31.01 g/L). Taken together, this study has attained an efficient VHB expression cassette for oxygen transfer and γ-PGA synthesis, which could also be applied in the production of other metabolites.
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Affiliation(s)
- Qing Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Yaozhong Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Lin Gao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Jian'gang Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
- Wuhan Junan Biotechnology Co. Ltd., Wuhan, China
| | - Xin Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Dongbo Cai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Dong Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
- Corresponding author. 368 Youyi Avenue, Wuchang District, Wuhan, 430062, Hubei, PR China.
| | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, 430062, PR China
- Corresponding author. 368 Youyi Avenue, Wuchang District, Wuhan, 430062, Hubei, PR China.
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A novel strategy of feeding nitrate for cost-effective production of poly-γ-glutamic acid from crude glycerol by Bacillus licheniformis WX-02. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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7
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Tong T, Chen X, Hu G, Wang XL, Liu GQ, Liu L. Engineering microbial metabolic energy homeostasis for improved bioproduction. Biotechnol Adv 2021; 53:107841. [PMID: 34610353 DOI: 10.1016/j.biotechadv.2021.107841] [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: 06/16/2021] [Revised: 08/25/2021] [Accepted: 09/28/2021] [Indexed: 10/20/2022]
Abstract
Metabolic energy (ME) homeostasis is essential for the survival and proper functioning of microbial cell factories. However, it is often disrupted during bioproduction because of inefficient ME supply and excessive ME consumption. In this review, we propose strategies, including reinforcement of the capacity of ME-harvesting systems in autotrophic microorganisms; enhancement of the efficiency of ME-supplying pathways in heterotrophic microorganisms; and reduction of unessential ME consumption by microbial cells, to address these issues. This review highlights the potential of biotechnology in the engineering of microbial ME homeostasis and provides guidance for the higher efficient bioproduction of microbial cell factories.
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Affiliation(s)
- Tian Tong
- Hunan Provincial Key Laboratory for Forestry Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China; International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry and Technology, Changsha 410004, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Guipeng Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Xiao-Ling Wang
- Hunan Provincial Key Laboratory for Forestry Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China; International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry and Technology, Changsha 410004, China
| | - Gao-Qiang Liu
- Hunan Provincial Key Laboratory for Forestry Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China; International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry and Technology, Changsha 410004, China.
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China.
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Simultaneous production of poly-γ-glutamic acid and 2,3-butanediol by a newly isolated Bacillus subtilis CS13. Appl Microbiol Biotechnol 2020; 104:7005-7021. [PMID: 32642915 DOI: 10.1007/s00253-020-10755-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 05/26/2020] [Accepted: 06/24/2020] [Indexed: 12/28/2022]
Abstract
Bacillus subtilis naturally produces large amounts of 2,3-butanediol (2,3-BD) as a main by-product during poly-γ-glutamic acid (γ-PGA) production. 2,3-BD is a promising platform chemical in various industries, and co-production of the two chemicals has great economic benefits. Co-production of γ-PGA and 2,3-BD by a newly isolated B. subtilis CS13 was investigated here. The fermentation medium and culture parameters of the process were optimized using statistical methods. It was observed that sucrose, L-glutamic acid, ammonium citrate, and MgSO4·7H2O were favorable for γ-PGA and 2,3-BD co-production at culture pH of 6.5 and 37 °C. An optimal medium composed of 119.8 g/L sucrose, 48.8 g/L L-glutamic acid, 21.1 g/L ammonium citrate, and 3.2 g/L MgSO4·7H2O was obtained by response surface methodology (RSM). The results show that the titers of γ-PGA and 2,3-BD reached 27.8 ± 0.9 g/L at 24 h and 57.1 ± 1.3 g/L at 84 h with the optimized medium, respectively. γ-PGA and 2,3-BD production by B. subtilis CS13 was significantly enhanced in fed-batch fermentations. γ-PGA (36.5 ± 1.1 g/L, productivity of 1.22 ± 0.04 g/L/h) and 2,3-BD concentrations (119.6 ± 2.8 g/L, productivity of 2.49 ± 0.66 g/L/h) were obtained in the optimized medium with feeding sucrose. The co-production of 2,3-BD and γ-PGA provides a new perspective for industrial production of γ-PGA and 2,3-BD. Key points • A strategy for co-production of γ-PGA and 2,3-BD was developed. • The culture parameters for the co-production of γ-PGA and 2,3-BD were studied. • RSM was used to optimize the medium for γ-PGA and 2,3-BD co-production. • 36.5 g/L γ-PGA and 119.6 g/L 2,3-BD were obtained from the optimum medium in fed-batch fermentation.
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9
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Wang D, Hwang JS, Kim DH, Lee S, Kim DH, Joe MH. A newly isolated Bacillus siamensis SB1001 for mass production of poly-γ-glutamic acid. Process Biochem 2020. [DOI: 10.1016/j.procbio.2019.11.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Lü C, Ge Y, Cao M, Guo X, Liu P, Gao C, Xu P, Ma C. Metabolic Engineering of Bacillus licheniformis for Production of Acetoin. Front Bioeng Biotechnol 2020; 8:125. [PMID: 32154242 PMCID: PMC7047894 DOI: 10.3389/fbioe.2020.00125] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/10/2020] [Indexed: 11/13/2022] Open
Abstract
Acetoin is a potential platform compound for a variety of chemicals. Bacillus licheniformis MW3, a thermophilic and generally regarded as safe (GRAS) microorganism, can produce 2,3-butanediol with a high concentration, yield, and productivity. In this study, B. licheniformis MW3 was metabolic engineered for acetoin production. After deleting two 2,3-butanediol dehydrogenases encoding genes budC and gdh, an engineered strain B. licheniformis MW3 (ΔbudCΔgdh) was constructed. Using fed-batch fermentation of B. licheniformis MW3 (ΔbudCΔgdh), 64.2 g/L acetoin was produced at a productivity of 2.378 g/[L h] and a yield of 0.412 g/g from 156 g/L glucose in 27 h. The fermentation process exhibited rather high productivity and yield of acetoin, indicating that B. licheniformis MW3 (ΔbudCΔgdh) might be a promising acetoin producer.
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Affiliation(s)
- Chuanjuan Lü
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Yongsheng Ge
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Menghao Cao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Xiaoting Guo
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Peihai Liu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Chao Gao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
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11
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Cai D, Chen Y, He P, Wang S, Mo F, Li X, Wang Q, Nomura CT, Wen Z, Ma X, Chen S. Enhanced production of poly-γ-glutamic acid by improving ATP supply in metabolically engineered Bacillus licheniformis. Biotechnol Bioeng 2018; 115:2541-2553. [PMID: 29940069 DOI: 10.1002/bit.26774] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/14/2018] [Accepted: 06/21/2018] [Indexed: 11/07/2022]
Abstract
Poly-γ-glutamic acid (γ-PGA) is an important multifunctional biopolymer with various applications, for which adenosine triphosphate (ATP) supply plays a vital role in biosynthesis. In this study, the enhancement of γ-PGA production was attempted through various approaches of improving ATP supply in the engineered strains of Bacillus licheniformis. The first approach is to engineer respiration chain branches of B. licheniformis, elimination of cytochrome bd oxidase branch reduced the maintenance coefficient, leading to a 19.27% increase of γ-PGA yield. The second approach is to introduce Vitreoscilla hemoglobin (VHB) into recombinant B. licheniformis, led to a 13.32% increase of γ-PGA yield. In the third approach, the genes purB and adK in ATP-biosynthetic pathway were respectively overexpressed, with the AdK overexpressed strain increased γ-PGA yield by 14.69%. Our study also confirmed that the respiratory nitrate reductase, NarGHIJ, is responsible for the conversion of nitrate to nitrite, and assimilatory nitrate reductase NasBC is for conversion of nitrite to ammonia. Both NarGHIJ and NasBC were positively regulated by the two-component system ResD-ResE, and overexpression of NarG, NasC, and ResD also improved the ATP supply and the consequent γ-PGA yield. Based on the above individual methods, a method of combining the deletion of cydBC gene and overexpression of genes vgB, adK, and resD were used to enhance ATP content of the cells to 3.53 μmol/g of DCW, the mutant WX-BCVAR with this enhancement produced 43.81 g/L of γ-PGA, a 38.64% improvement compared to wild-type strain WX-02. Collectively, our results demonstrate that improving ATP content in B. licheniformis is an efficient strategy to improve γ-PGA production.
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Affiliation(s)
- Dongbo Cai
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Yaozhong Chen
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Penghui He
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Shiyi Wang
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Fei Mo
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Xin Li
- Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, School of food and biological engineering, Hubei University of Technology, Wuhan, China
| | - Qin Wang
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Christopher T Nomura
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
- Department of Chemistry, The State University of New York, College of Environmental Science and Forestry (SUNY ESF), Iowa State University, Syracuse, New York
| | - Zhiyou Wen
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
- Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa
| | - Xin Ma
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
| | - Shouwen Chen
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, China
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12
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Cai D, Hu S, Chen Y, Liu L, Yang S, Ma X, Chen S. Enhanced Production of Poly-γ-glutamic acid by Overexpression of the Global Anaerobic Regulator Fnr in Bacillus licheniformis WX-02. Appl Biochem Biotechnol 2018; 185:958-970. [PMID: 29388009 DOI: 10.1007/s12010-018-2693-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/03/2018] [Indexed: 10/18/2022]
Abstract
Poly-γ-glutamic acid is a multi-functional biopolymer with various applications. ATP supply plays an important role in poly-γ-glutamic acid (γ-PGA) synthesis. Global anaerobic regulator Fnr plays a key role in anaerobic adaptation and nitrate respiration, which might affect ATP generation during γ-PGA synthesis. In this study, we have improved γ-PGA production by overexpression of Fnr in Bacillus licheniformis WX-02. First, the gene fnr was knocked out in WX-02, and the γ-PGA yields have no significant differences between WX-02 and the fnr-deficient strain WXΔfnr in the medium without nitrate (BFC medium). However, the γ-PGA yield of 8.95 g/L, which was produced by WXΔfnr in the medium with nitrate addition (BFCN medium), decreased by 74% compared to WX-02 (34.53 g/L). Then, the fnr complementation strain WXΔfnr/pHY-fnr restored the γ-PGA synthesis capability, and γ-PGA yield was increased by 13% in the Fnr overexpression strain WX/pHY-fnr (39.96 g/L) in BFCN medium, compared to WX/pHY300 (35.41 g/L). Furthermore, the transcriptional levels of narK, narG, and hmp were increased by 5.41-, 4.93-, and 3.93-fold in WX/pHY-fnr, respectively, which led to the increases of nitrate consumption rate and ATP supply for γ-PGA synthesis. Collectively, Fnr affects γ-PGA synthesis mainly through manipulating the expression level of nitrate metabolism, and this study provides a novel strategy to improve γ-PGA production by overexpression of Fnr.
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Affiliation(s)
- Dongbo Cai
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Shiying Hu
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Yaozhong Chen
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Li Liu
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Shihui Yang
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Xin Ma
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China.
| | - Shouwen Chen
- Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062, China.
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13
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Microbial production of poly-γ-glutamic acid. World J Microbiol Biotechnol 2017; 33:173. [DOI: 10.1007/s11274-017-2338-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 08/30/2017] [Indexed: 10/18/2022]
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Improvement of glycerol catabolism in Bacillus licheniformis for production of poly-γ-glutamic acid. Appl Microbiol Biotechnol 2017; 101:7155-7164. [PMID: 28804802 DOI: 10.1007/s00253-017-8459-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 07/08/2017] [Accepted: 07/30/2017] [Indexed: 01/08/2023]
Abstract
Bacillus licheniformis WX-02 is a well-studied strain to produce poly-γ-glutamic acid (γ-PGA) with numerous applications. This study is to improve WX-02 strain's capability of assimilating glycerol, a major byproduct of biofuels industries, through metabolic manipulation. Through gene knockout, the GlpK pathway was identified as the sole functional glycerol catabolism pathway, while the DhaK pathway was inactive for this strain under either aerobic or anaerobic conditions. The enhancement of glycerol utilization was attempted by substituting the native glpFK promoter with the constitutive promoter (P43), ytzE promoter (PytzE), and bacABC operon promoter (PbacA), respectively. The glycerol consumptions of the corresponding mutant strains WX02-P43glpFK, WX02-PytzEglpFK, and WX02-PbacAglpFK were 30.9, 26.42, and 18.8% higher than that of the WX-02 strain, respectively. The γ-PGA concentrations produced by the three mutant strains were 33.71, 23.39, and 30.05% higher than that of WX-02 strain, respectively. When biodiesel-derived crude glycerol was used as the carbon source, the mutant WX02-P43glpFK produced 16.63 g L-1 of γ-PGA, with a productivity of 0.35 g L-1 h-1. Collectively, this study demonstrated that glycerol can be used as an effective substrate for producing γ-PGA by metabolic engineering B. licheniformis strains.
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Glutamate dehydrogenase (RocG) in Bacillus licheniformis WX-02: Enzymatic properties and specific functions in glutamic acid synthesis for poly-γ-glutamic acid production. Enzyme Microb Technol 2017; 99:9-15. [DOI: 10.1016/j.enzmictec.2017.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 01/03/2017] [Accepted: 01/05/2017] [Indexed: 11/21/2022]
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A novel approach to improve poly-γ-glutamic acid production by NADPH Regeneration in Bacillus licheniformis WX-02. Sci Rep 2017; 7:43404. [PMID: 28230096 PMCID: PMC5322528 DOI: 10.1038/srep43404] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 01/24/2017] [Indexed: 01/15/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is an important biochemical product with a variety of applications. This work reports a novel approach to improve γ-PGA through over expression of key enzymes in cofactor NADPH generating process for NADPH pool. Six genes encoding the key enzymes in NADPH generation were over-expressed in the γ-PGA producing strain B. licheniformis WX-02. Among various recombinants, the strain over-expressing zwf gene (coding for glucose-6-phosphate dehydrogenase), WX-zwf, produced the highest γ-PGA concentration (9.13 g/L), 35% improvement compared to the control strain WX-pHY300. However, the growth rates and glucose uptake rates of the mutant WX-zwf were decreased. The transcriptional levels of the genes pgsB and pgsC responsible for γ-PGA biosynthesis were increased by 8.21- and 5.26-fold, respectively. The Zwf activity of the zwf over expression strain increased by 9.28-fold, which led to the improvement of the NADPH generation, and decrease of accumulation of by-products acetoin and 2,3-butanediol. Collectively, these results demonstrated that NADPH generation via over-expression of Zwf is as an effective strategy to improve the γ-PGA production in B. licheniformis.
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Mitsunaga H, Meissner L, Palmen T, Bamba T, Büchs J, Fukusaki E. Metabolome analysis reveals the effect of carbon catabolite control on the poly(γ-glutamic acid) biosynthesis of Bacillus licheniformis ATCC 9945. J Biosci Bioeng 2015; 121:413-9. [PMID: 26419706 DOI: 10.1016/j.jbiosc.2015.08.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 07/30/2015] [Accepted: 08/21/2015] [Indexed: 12/24/2022]
Abstract
Poly(γ-glutamic acid) (PGA) is a polymer composed of L- and/or D-glutamic acids that is produced by Bacillus sp. Because the polymer has various features as water soluble, edible, non-toxic and so on, it has attracted attention as a candidate for many applications such as foods, cosmetics and so on. However, although it is well known that the intracellular metabolism of Bacillus sp. is mainly regulated by catabolite control, the effect of the catabolite control on the PGA producing Bacillus sp. is largely unknown. This study is the first report of metabolome analysis on the PGA producing Bacillus sp. that reveals the effect of carbon catabolite control on the metabolism of PGA producing Bacillus licheniformis ATCC 9945. Results showed that the cells cultivated in glycerol-containing medium showed higher PGA production than the cells in glucose-containing medium. Furthermore, metabolome analysis revealed that the activators of CcpA and CodY, global regulatory proteins of the intracellular metabolism, accumulated in the cells cultivated in glycerol-containing and glucose-containing medium, respectively, with CodY apparently inhibiting PGA production. Moreover, the cells seemed to produce glutamate from citrate and ammonium using glutamine synthetase/glutamate synthase. Pulsed addition of di-ammonium hydrogen citrate, as suggested by the metabolome result, was able to achieve the highest value so far for PGA production in B. licheniformis.
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Affiliation(s)
- Hitoshi Mitsunaga
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871 Osaka, Japan.
| | - Lena Meissner
- AVT - Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringer Weg 1, 52074 Aachen, Germany.
| | - Thomas Palmen
- AVT - Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringer Weg 1, 52074 Aachen, Germany.
| | - Takeshi Bamba
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871 Osaka, Japan; Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8285 Fukuoka, Japan.
| | - Jochen Büchs
- AVT - Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringer Weg 1, 52074 Aachen, Germany.
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871 Osaka, Japan.
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Influence of nitrogen source and pH value on undesired poly(γ-glutamic acid) formation of a protease producing Bacillus licheniformis strain. J Ind Microbiol Biotechnol 2015; 42:1203-15. [PMID: 26153501 DOI: 10.1007/s10295-015-1640-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 06/10/2015] [Indexed: 10/23/2022]
Abstract
Bacillus spp. are used for the production of industrial enzymes but are also known to be capable of producing biopolymers such as poly(γ-glutamic acid). Biopolymers increase the viscosity of the fermentation broth, thereby impairing mixing, gas/liquid mass and heat transfer in any bioreactor system. Undesired biopolymer formation has a significant impact on the fermentation and downstream processing performance. This study shows how undesirable poly(γ-glutamic acid) formation of an industrial protease producing Bacillus licheniformis strain was prevented by switching the nitrogen source from ammonium to nitrate. The viscosity was reduced from 32 to 2.5 mPa s. A constant or changing pH value did not influence the poly(γ-glutamic acid) production. Protease production was not affected: protease activities of 38 and 46 U mL(-1) were obtained for ammonium and nitrate, respectively. With the presented results, protease production with industrial Bacillus strains is now possible without the negative impact on fermentation and downstream processing by undesired poly(γ-glutamic acid) formation.
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