1
|
Sun X, Cai Y, Wang D. Enhanced Poly-γ-Glutamic Acid Production by a Newly Isolated Bacillus halotolerans F29. J Microbiol 2024:10.1007/s12275-024-00153-w. [PMID: 39164498 DOI: 10.1007/s12275-024-00153-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/20/2024] [Accepted: 06/09/2024] [Indexed: 08/22/2024]
Abstract
Poly-γ-glutamic acid (γ-PGA) is a promising biopolymer for various applications. In this study, we isolated a novel γ-PGA-producing strain, Bacillus halotolerans F29. The one-factor-at-a-time method was used to investigate the influence of carbon sources, nitrogen sources, and culture parameters on γ-PGA production. The optimal carbon and nitrogen sources were sucrose and (NH4)2SO4, respectively. The optimal culture conditions for γ-PGA production were determined to be 37 °C and a pH of 5.5. Response surface methodology was used to determine the optimum medium components: 77.6 g/L sucrose, 43.0 g/L monosodium glutamate, and 2.2 g/L K2HPO4. The γ-PGA titer increased significantly from 8.5 ± 0.3 g/L to 20.7 ± 0.7 g/L when strain F29 was cultivated in the optimized medium. Furthermore, the γ-PGA titer reached 50.9 ± 1.5 g/L with a productivity of 1.33 g/L/h and a yield of 2.23 g of γ-PGA/g of L-glutamic acid with the optimized medium in fed-batch fermentation. The maximum γ-PGA titer reached 45.3 ± 1.1 g/L, with a productivity of 1.06 g/L/h when molasses was used as a carbon source. It should be noted that the γ-PGA yield in this study was the highest of all reported studies, indicating great potential for the industrial production of γ-PGA.
Collapse
Affiliation(s)
- Xiaorong Sun
- Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China
| | - Yaoyu Cai
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, People's Republic of China.
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
| | - Dexin Wang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, People's Republic of China.
- CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| |
Collapse
|
2
|
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%.
Collapse
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
| |
Collapse
|
3
|
Guo Y, Liu Y, Yang Z, Chen G, Liang Z, Zeng W. Enhanced Production of Poly-γ-glutamic Acid by Bacillus subtilis Using Stage-controlled Fermentation and Viscosity Reduction Strategy. Appl Biochem Biotechnol 2024; 196:1527-1543. [PMID: 37432638 DOI: 10.1007/s12010-023-04644-1] [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] [Accepted: 07/01/2023] [Indexed: 07/12/2023]
Abstract
In this study, the production of poly-γ-glutamic acid (PGA) by Bacillus subtilis using stage-controlled fermentation and viscosity reduction strategy was investigated in detail. Based on the single-factor optimization experiment, temperature (42 °C and 37 °C), pH (7.0 and uncontrolled), aeration rate (1.2 vvm and 1.0 vvm), and agitation speed (700 rpm and 500 rpm) were selected for the two-stage controlled fermentation (TSCF). The time points for the TSCF of temperature, pH, aeration rate, and agitation speed were set at 18.52 h, 2.82 h, 5.92 h, and 3.62 h, respectively, based on the kinetic analysis. A PGA titer of 19.79 ~ 22.17 g/L was obtained from the TSCF, which did not increase significantly than that (21.25 ± 1.26 g/L) of non-stage controlled fermentation (NSCF). This may be due to the high viscosity and low dissolved oxygen of the PGA fermentation broth. Thus, the TSCF combined with a viscosity reduction strategy was developed to further improve the production of PGA. The PGA titer reached 25.00 ~ 30.67 g/L, which increased by 17.66 ~ 32.94% to that of NSCF. This study provided a valuable reference for the development of process control strategies for high-viscosity fermentation systems.
Collapse
Affiliation(s)
- 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, 100 Daxue Road, Nanning, 530004, 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, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Zejian Yang
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Guiguang Chen
- 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, 100 Daxue Road, Nanning, 530004, 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, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - 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, 1 Zhiyuan Road, Guilin, 541199, 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, 100 Daxue Road, Nanning, 530004, Guangxi, China.
| |
Collapse
|
4
|
Adilkhanova A, Ormantayeva A, Kaziullayeva A, Olaifa K, Eghtesadi N, Abbas AH, Calvio C, Pham TT, Ajunwa OM, Marsili E. Electrofermentation increases concentration of poly γ-glutamic acid in Bacillus subtilis biofilms. Microb Biotechnol 2024; 17:e14426. [PMID: 38497275 PMCID: PMC10945395 DOI: 10.1111/1751-7915.14426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 02/01/2024] [Indexed: 03/19/2024] Open
Abstract
Fluctuations in redox conditions in bioprocesses can alter the end-products, reduce their concentration, and lengthen the process time. Electrofermentation enables rapid metabolic modulation of biosynthesis and allows control of redox imbalances in biofilm-based fermentation processes. In this study, electrofermentation is used to boost the production of the bacterial biopolymer poly-γ-glutamic acid (γ-PGA) from Bacillus subtilis ATCC 6051. When compared to control experiments (3.3 ± 0.99 g L-1 ), the application of an electrode potential E = 0.4 V versus Ag/AgCl results in a more than two-fold increase in the production of γ-PGA (9.13 ± 1.4 g L-1 ). Using an engineered B. subtilis strain, in which γ-PGA production is driven by isopropyl β-d-1-thiogalactopyranoside, electrofermentation improves polymer concentrations from 15.4 ± 1.5 to 23.1 ± 1.6 versus g L-1 . These results confirm that electrofermentation conditions can be adopted to increase the concentration of γ-PGA and perhaps other extracellular biopolymers in industrial strains.
Collapse
Affiliation(s)
- Alina Adilkhanova
- Biofilm Laboratory, Department of Chemical and Materials Engineering, School of Engineering and Digital SciencesNazarbayev UniversityAstanaKazakhstan
| | - Anar Ormantayeva
- Biofilm Laboratory, Department of Chemical and Materials Engineering, School of Engineering and Digital SciencesNazarbayev UniversityAstanaKazakhstan
| | - Aisholpan Kaziullayeva
- Biofilm Laboratory, Department of Chemical and Materials Engineering, School of Engineering and Digital SciencesNazarbayev UniversityAstanaKazakhstan
| | - Kayode Olaifa
- Biofilm Laboratory, Department of Chemical and Materials Engineering, School of Engineering and Digital SciencesNazarbayev UniversityAstanaKazakhstan
| | - Neda Eghtesadi
- Biofilm Laboratory, Department of Chemical and Materials Engineering, School of Engineering and Digital SciencesNazarbayev UniversityAstanaKazakhstan
| | - Azza H. Abbas
- Department of Petroleum Engineering, School of Mining and GeosciencesNazarbayev UniversityAstanaKazakhstan
| | - Cinzia Calvio
- Nottingham Ningbo China Beacons of Excellence Research and Innovation InstituteNingboChina
| | - Tri T. Pham
- Department of Biology and BiotechnologyUniversità degli Studi di PaviaPaviaItaly
| | - Obinna M. Ajunwa
- Biofilm Laboratory, Department of Chemical and Materials Engineering, School of Engineering and Digital SciencesNazarbayev UniversityAstanaKazakhstan
- Department of Biology, School of Sciences and HumanitiesNazarbayev UniversityAstanaKazakhstan
| | - Enrico Marsili
- Department of Biology, Faculty of Natural Sciences, Interdisciplinary Nanoscience CenterAarhus UniversityAarhusDenmark
| |
Collapse
|
5
|
Elbanna K, Alsulami FS, Neyaz LA, Abulreesh HH. Poly (γ) glutamic acid: a unique microbial biopolymer with diverse commercial applicability. Front Microbiol 2024; 15:1348411. [PMID: 38414762 PMCID: PMC10897055 DOI: 10.3389/fmicb.2024.1348411] [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: 12/02/2023] [Accepted: 01/19/2024] [Indexed: 02/29/2024] Open
Abstract
Microbial biopolymers have emerged as promising solutions for environmental pollution-related human health issues. Poly-γ-glutamic acid (γ-PGA), a natural anionic polymeric compound, is composed of highly viscous homo-polyamide of D and L-glutamic acid units. The extracellular water solubility of PGA biopolymer facilitates its complete biodegradation and makes it safe for humans. The unique properties have enabled its applications in healthcare, pharmaceuticals, water treatment, foods, and other domains. It is applied as a thickener, taste-masking agent, stabilizer, texture modifier, moisturizer, bitterness-reducing agent, probiotics cryoprotectant, and protein crystallization agent in food industries. γ-PGA is employed as a biological adhesive, drug carrier, and non-viral vector for safe gene delivery in tissue engineering, pharmaceuticals, and medicine. It is also used as a moisturizer to improve the quality of hair care and skincare cosmetic products. In agriculture, it serves as an ideal stabilizer, environment-friendly fertilizer synergist, plant-growth promoter, metal biosorbent in soil washing, and animal feed additive to reduce body fat and enhance egg-shell strength.
Collapse
Affiliation(s)
- Khaled Elbanna
- Department of Biology, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
- Research Laboratories Unit, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
- Department of Agricultural Microbiology, Faculty of Agriculture, Fayoum University, Fayoum, Egypt
| | - Fatimah S Alsulami
- Department of Biology, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
- Research Laboratories Unit, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Leena A Neyaz
- Department of Biology, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
- Research Laboratories Unit, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Hussein H Abulreesh
- Department of Biology, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
- Research Laboratories Unit, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
| |
Collapse
|
6
|
Qiao M, Zhang T, Miao M. Minced Beef Meat Paste Characteristics: Gel Properties, Water Distribution, and Microstructures Regulated by Medium Molecular Mass of γ-Poly-Glutamic Acid. Foods 2024; 13:510. [PMID: 38397487 PMCID: PMC10887638 DOI: 10.3390/foods13040510] [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: 01/09/2024] [Revised: 02/01/2024] [Accepted: 02/04/2024] [Indexed: 02/25/2024] Open
Abstract
The influences of various m-γ-PGA (0.08-0.20%, w/w) concentrations on the properties of minced beef meat paste in terms of rheological properties, texture, moisture distribution, and microstructures were evaluated. The results indicated that m-γ-PGA enhanced the water-holding capacity, gel strength, texture, and whiteness of the minced beef meat paste. Based on the microstructural results, m-γ-PGA helped form a more organized and compact gel, thereby limiting the migration of water through the gel matrix. In contrast to the control group, the water-holding property, gel strength, and whiteness of minced meat paste gels with m-γ-PGA content of 0.12% increased from 75.89%, 584.51 g·cm, and 61.83 to 79.91%, 780.87 g·cm, and 62.54, respectively (p < 0.05), exhibiting the highest water-holding property and gel strength. Thus, m-γ-PGA exhibits great potential for minced meat paste products as a healthy gel water retainer and enhancer in low-fat meat products.
Collapse
Affiliation(s)
- Mengmeng Qiao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; (M.Q.); (M.M.)
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Tao Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; (M.Q.); (M.M.)
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Ming Miao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; (M.Q.); (M.M.)
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Samal S, Banerjee S, Dey P, Rangarajan V. Production and characterization of a novel poly amino acid from a thermophilic bacterium, and preliminary testing of its coagulating potential for imminent wastewater treatment application. Int J Biol Macromol 2023; 246:125589. [PMID: 37385322 DOI: 10.1016/j.ijbiomac.2023.125589] [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: 04/23/2023] [Revised: 06/15/2023] [Accepted: 06/25/2023] [Indexed: 07/01/2023]
Abstract
The increasing demand for biopolymers across diverse fields, such as food, medicine, cosmetics, and environmental applications, has prompted researchers to explore novel molecules with enhanced functionalities that meet these demands. In this study, a thermophilic strain of Bacillus licheniformis was employed to produce a unique polyamino acid. This thermophilic isolate exhibited rapid growth at 50 °C in a sucrose mineral salts medium, resulting in a biopolymer concentration of 7.4 g/L. Interestingly, the biopolymer produced at different temperatures exhibited varying glass-transition temperatures (ranging from 87.86 °C to 104.11 °C) and viscosities (7.5 cP to 16.3 cP), suggesting that the fermentation temperature significantly influenced the degree of polymerization. Furthermore, the biopolymer was characterized using various techniques, including Thin Layer Chromatography (TLC), Fourier Transform Infrared (FTIR) spectroscopy, Liquid Chromatography-Electrospray Ionization-Mass Spectroscopy (LC-ESI MS), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry-Thermogravimetric Analysis (DSC-TGA). The results revealed that the obtained biopolymer was a poly amino acid, with poly-γ-glutamic acid as the major monomeric component in the polymer backbone with a few appendages of aspartic acid residues in its side chain. Finally, the biopolymer demonstrated significant coagulation potential for water treatment applications, as evidenced by coagulation studies conducted under varying pH conditions using kaolin-clay as a model precipitant.
Collapse
Affiliation(s)
- Subhranshu Samal
- Department of Chemical Engineering, Birla Institute of Technology and Science Pilani K.K. Birla Goa Campus, 403726, India
| | - Subhadeep Banerjee
- Department of Chemistry, Birla Institute of Technology and Science Pilani K.K. Birla Goa Campus, 403726, India
| | - Pinaki Dey
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
| | - Vivek Rangarajan
- Department of Chemical Engineering, Birla Institute of Technology and Science Pilani K.K. Birla Goa Campus, 403726, India.
| |
Collapse
|
9
|
Wang D, Fu X, Zhou D, Gao J, Bai W. Engineering of a newly isolated Bacillus tequilensis BL01 for poly-γ-glutamic acid production from citric acid. Microb Cell Fact 2022; 21:276. [PMID: 36581997 PMCID: PMC9798646 DOI: 10.1186/s12934-022-01994-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/14/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Poly γ-glutamic acid (γ-PGA) is a promising biopolymer for various applications. For glutamic acid-independent strains, the titer of γ-PGA is too low to meet the industrial demand. In this study, we isolated a novel γ-PGA-producing strain, Bacillus tequilensis BL01, and multiple genetic engineering strategies were implemented to improve γ-PGA production. RESULTS First, the one-factor-at-a-time method was used to investigate the influence of carbon and nitrogen sources and temperature on γ-PGA production. The optimal sources of carbon and nitrogen were sucrose and (NH4)2SO4 at 37 °C, respectively. Second, the sucA, gudB, pgdS, and ggt genes were knocked out simultaneously, which increased the titer of γ-PGA by 1.75 times. Then, the titer of γ-PGA increased to 18.0 ± 0.3 g/L by co-overexpression of the citZ and pyk genes in the mutant strain. Furthermore, the γ-PGA titer reached 25.3 ± 0.8 g/L with a productivity of 0.84 g/L/h and a yield of 1.50 g of γ-PGA/g of citric acid in fed-batch fermentation. It should be noted that this study enables the synthesis of low (1.84 × 105 Da) and high (2.06 × 106 Da) molecular weight of γ-PGA by BL01 and the engineering strain. CONCLUSION The application of recently published strategies to successfully improve γ-PGA production for the new strain B. tequilensis BL01 is reported. The titer of γ-PGA increased 2.17-fold and 1.32-fold compared with that of the wild type strain in the flask and 5 L fermenter. The strain shows excellent promise as a γ-PGA producer compared with previous studies. Meanwhile, different molecular weights of γ-PGA were obtained, enhancing the scope of application in industry.
Collapse
Affiliation(s)
- Dexin Wang
- grid.9227.e0000000119573309CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308 China
| | - Xiaoping Fu
- grid.9227.e0000000119573309CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308 China
| | - Dasen Zhou
- grid.413109.e0000 0000 9735 6249College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Jiaqi Gao
- grid.9227.e0000000119573309CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing, 100049 China
| | - Wenqin Bai
- grid.9227.e0000000119573309CAS Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308 China
| |
Collapse
|
10
|
Chen X, Shang C, Zhang H, Sun C, Zhang G, Liu L, Li C, Li A, Du P. Effects of Alkali Stress on the Growth and Menaquinone-7 Metabolism of Bacillus subtilis natto. Front Microbiol 2022; 13:899802. [PMID: 35572665 PMCID: PMC9096614 DOI: 10.3389/fmicb.2022.899802] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 04/08/2022] [Indexed: 11/28/2022] Open
Abstract
Menaquinone-7 (MK-7) is an important vitamin K2, synthesized from the menaquinone parent ring and seven isoprene side chains. Presently, the synthesis of MK-7 stimulated by environmental stress primarily focuses on oxygen stress, while the effect of alkali stress is rarely studied. Therefore, this study researched the effects of alkali stress on the fermentation performance and gene expression of Bacillus subtilis natto. The organism’s growth characteristics, biomass, sporogenesis, MK-7 biosynthesis, and gene expression were analyzed. After a pH 8.5 stress adaptation treatment for 0.5 h and subsequent fermentation at pH 8.5, which promoted the growth of the strain and inhibited the spore formation rate. In addition, biomass was significantly increased (P < 0.05). The conversion rate of glycerol to MK-7 was 1.68 times higher than that of the control group, and the yield of MK-7 increased to 2.10 times. Transcriptomic analysis showed that the MK-7 high-yielding strain had enhanced carbon source utilization, increased glycerol and pyruvate metabolism, enhanced the Embden-Meyerhof pathway (EMP), tricarboxylic acid (TCA) circulation flux, and terpenoid biosynthesis pathway, and promoted the accumulation of acetyl-CoA, the side-chain precursor of isoprene. At the same time, the up-regulation of transketolase increased the metabolic flux of the pentose phosphate (HMP) pathway, which was conducive to the accumulation of D-erythrose 4-phosphate, the precursor of the menadione parent ring. This study’s results contribute to a better understanding of the effects of environmental stress on MK-7 fermentation by Bacillus subtilis natto and the molecular regulatory mechanism of MK-7 biosynthesis.
Collapse
Affiliation(s)
- Xiaoqian Chen
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| | - Chao Shang
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| | - Huimin Zhang
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| | - Cuicui Sun
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| | - Guofang Zhang
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| | - Libo Liu
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| | - Chun Li
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China.,Heilongjiang Green Food Science Research Institute, Harbin, China
| | - Aili Li
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China.,Heilongjiang Green Food Science Research Institute, Harbin, China
| | - Peng Du
- Key Laboratory of Dairy Science, College of Food Science, Northeast Agricultural University, Harbin, China
| |
Collapse
|
11
|
Li D, Hou L, Gao Y, Tian Z, Fan B, Wang F, Li S. Recent Advances in Microbial Synthesis of Poly-γ-Glutamic Acid: A Review. Foods 2022; 11:foods11050739. [PMID: 35267372 PMCID: PMC8909396 DOI: 10.3390/foods11050739] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/12/2022] [Accepted: 02/26/2022] [Indexed: 02/01/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is a natural, safe, non-immunogenic, biodegradable, and environmentally friendly glutamic biopolymer. γ-PGA has been regarded as a promising bio-based materials in the food field, medical field, even in environmental engineering field, and other industrial fields. Microbial synthesis is an economical and effective way to synthesize γ-PGA. Bacillus species are the most widely studied producing strains. γ-PGA biosynthesis involves metabolic pathway of racemization, polymerization, transfer, and catabolism. Although microbial synthesis of γ-PGA has already been used extensively, productivity and yield remain the major constraints for its industrial application. Metabolic regulation is an attempt to solve the above bottleneck problems and meet the demands of commercialization. Therefore, it is important to understand critical factors that influence γ-PGA microbial synthesis in depth. This review focuses on production strains, biosynthetic pathway, and metabolic regulation. Moreover, it systematically summarizes the functional properties, purification procedure, and industrial application of γ-PGA.
Collapse
Affiliation(s)
- Danfeng Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuan Ming Yuan West Road, Beijing 100193, China; (D.L.); (L.H.); (Y.G.); (Z.T.); (B.F.)
| | - Lizhen Hou
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuan Ming Yuan West Road, Beijing 100193, China; (D.L.); (L.H.); (Y.G.); (Z.T.); (B.F.)
| | - Yaxin Gao
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuan Ming Yuan West Road, Beijing 100193, China; (D.L.); (L.H.); (Y.G.); (Z.T.); (B.F.)
| | - Zhiliang Tian
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuan Ming Yuan West Road, Beijing 100193, China; (D.L.); (L.H.); (Y.G.); (Z.T.); (B.F.)
| | - Bei Fan
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuan Ming Yuan West Road, Beijing 100193, China; (D.L.); (L.H.); (Y.G.); (Z.T.); (B.F.)
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fengzhong Wang
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (F.W.); (S.L.); Tel.: +86-010-62815977 (F.W.); +86-010-62810295 (S.L.)
| | - Shuying Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuan Ming Yuan West Road, Beijing 100193, China; (D.L.); (L.H.); (Y.G.); (Z.T.); (B.F.)
- Correspondence: (F.W.); (S.L.); Tel.: +86-010-62815977 (F.W.); +86-010-62810295 (S.L.)
| |
Collapse
|
12
|
Wang L, Chen S, Yu B. Poly-γ-glutamic acid: Recent achievements, diverse applications and future perspectives. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2021.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
13
|
An integrated strategy for recovery and purification of poly-γ-glutamic acid from fermentation broth and its techno-economic analysis. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
14
|
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.
Collapse
|
15
|
Cao X, Che Z, Zhou B, Guan B, Chen G, Zeng W, Liang Z. Investigations in ultrasound-assisted anticoagulant production by marine Bacillus subtilis ZHX. ULTRASONICS SONOCHEMISTRY 2020; 64:104994. [PMID: 32044681 DOI: 10.1016/j.ultsonch.2020.104994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 06/10/2023]
Abstract
Anticoagulants are the main drugs for the prevention and treatment of thromboembolism. However, most of the present anticoagulants have shortcomings and novel anticoagulants are in great demand. Marine microorganisms are an important source of new drugs. Therefore, in this study, ultrasound was applied to enhance anticoagulant accumulation by marine Bacillus subtilis ZHX. Ultrasound parameters were optimized by single-factor experiments exploring the effects of ultrasound power, duration, duty cycle and the cell growth phases. The optimum conditions were exponential prophase (5 h) with 25 kHz frequency, 140 W power, and a 40% duty cycle for 5 min. The maximum anticoagulant activity (55.36 U/mL) was 1.73 times that of the control group, and the fermentation time was shortened by 3 h. Under optimal conditions, ultrasound increased the carbon utilization by Bacillus subtilis ZHX without significant changes in morphology, favoring cell growth and anticoagulant production. However, excessive ultrasound caused intracellular damage, which inhibited biomass accumulation, decreasing anticoagulant activity and even leading to cell rupture. This is the first report on the use of ultrasound to enhance anticoagulant production by Bacillus, and it provides useful information for scaling-up the process.
Collapse
Affiliation(s)
- Xiaoyan Cao
- 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, China
| | - Zhiqun Che
- 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, China
| | - Bo Zhou
- 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, China
| | - Baohu Guan
- 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, China
| | - Guiguang Chen
- 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, China
| | - Wei Zeng
- 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, 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, China.
| |
Collapse
|
16
|
Wang D, Kim H, Lee S, Kim DH, Joe MH. High-level production of poly-γ-glutamic acid from untreated molasses by Bacillus siamensis IR10. Microb Cell Fact 2020; 19:101. [PMID: 32398084 PMCID: PMC7216703 DOI: 10.1186/s12934-020-01361-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 04/30/2020] [Indexed: 01/01/2023] Open
Abstract
Background Poly-γ-glutamic acid (γ-PGA) is a promising biopolymer and has been applied in many fields. Bacillus siamensis SB1001 was a newly isolated poly-γ-glutamic acid producer with sucrose as its optimal carbon source. To improve the utilization of carbon source, and then molasses can be effectively used for γ-PGA production, 60cobalt gamma rays was used to mutate the genes of B. siamensis SB1001. Results Bacillus siamensis IR10 was screened for the production of γ-PGA from untreated molasses. In batch fermentation, 17.86 ± 0.97 g/L γ-PGA was obtained after 15 h, which is 52.51% higher than that of its parent strain. Fed-batch fermentation was performed to further improve the yield of γ-PGA with untreated molasses, yielding 41.40 ± 2.01 g/L of γ-PGA with a productivity of 1.73 ± 0.08 g/L/h. An average γ-PGA productivity of 1.85 g/L/h was achieved in the repeated fed-batch fermentation. This is the first report of such a high γ-PGA productivity. The analysis of the enzyme activities showed that they were affected by the carbon sources, enhanced ICDH and GDH, and decreased ODHC, which are important for γ-PGA production. Conclusion These results suggest that untreated molasses can be used for economical and industrial-scale production of γ-PGA by B. siamensis IR10.![]()
Collapse
Affiliation(s)
- Dexin Wang
- Radiation Utilization and Facilities Management Division, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, 56212, Republic of Korea.,Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics,Center for Fungal Pathogenesis, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Hyangmi Kim
- Bacteria Research Team, Nakdonggang National Institute of Biological Resources (NNIBR), Sangju, 37242, Republic of Korea
| | - Sungbeom Lee
- Radiation Research Division, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, 56212, Republic of Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Dae-Hyuk Kim
- Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics,Center for Fungal Pathogenesis, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Min-Ho Joe
- Radiation Utilization and Facilities Management Division, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, 56212, Republic of Korea.
| |
Collapse
|
17
|
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]
|
18
|
Economical production of agricultural γ-polyglutamic acid using industrial wastes by Bacillus subtilis. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.03.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
19
|
Stimulatory effects of amino acids on γ-polyglutamic acid production by Bacillus subtilis. Sci Rep 2018; 8:17934. [PMID: 30560878 PMCID: PMC6298950 DOI: 10.1038/s41598-018-36439-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 11/20/2018] [Indexed: 11/08/2022] Open
Abstract
This paper is about study to increase the γ-PGA yield by developing new methods. The effect of various amino acids on production of γ-PGA by Bacillus subtilis Z15 was investigated. The γ-PGA yield was increased 23.18%, 12.15% and 31.46%, respectively, with 3 g/L aspartic acid (0 h), 1.5 g/L phenylalanine (0 h) and 7 g/L glutamic acid (24 h). Additonally, crude extract of glutamic acid after isoelectric crystallization (CEGA)could be a replacement for glutamate for γ-PGA production. Then, response surface methodology (RSM) was used for further optimization. The final media ingredient of amino acids were obtained as follow: CEGA 9 g/L, aspartic acid 4 g/L, phenylalanine 1.55 g/L. By applying this receipt in 5-L bioreactor, the γ-PGA yield reached 42.92 ± 0.23 g/L after 44 h, which is 63.1% higher than the control without amino acids for production. In addition, amino acids could shorten the lag phase and the average fermentation time (44 h versus 48 h). Fermentation with amino acids addition can be an positive option for γ-PGA production.
Collapse
|
20
|
Zeng W, Chen G, Guo Y, Zhang B, Dong M, Wu Y, Wang J, Che Z, Liang Z. Production of poly-γ-glutamic acid by a thermotolerant glutamate-independent strain and comparative analysis of the glutamate dependent difference. AMB Express 2017; 7:213. [PMID: 29177886 PMCID: PMC5701898 DOI: 10.1186/s13568-017-0512-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 11/11/2017] [Indexed: 01/28/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is a promising microbial polymer with wide applications in industry, agriculture and medicine. In this study, a novel glutamate-independent γ-PGA producing strain with thermotolerant characteristics was isolated and identified as Bacillus subtilis GXG-5, then its product was also characterized. The fermentation process was optimized by single-factor tests, and results showed that high temperature (50 °C) was especially suitable for the γ-PGA production by GXG-5. The γ-PGA yield reached 19.50 ± 0.75 g/L with substrate conversion efficiency of 78% at 50 °C in 10 L fermentor. Comparison of GXG-5 and GXA-28 (glutamate-dependent strain) under respective optimal fermentation conditions, the γ-PGA yield of GXG-5 was 19.0% higher than that of GXA-28, and GXG-5 was also superior to GXA-28 in the availability of carbon sources and substrates. Furthermore, the glutamate dependent difference between GXA-28 and GXG-5 was analyzed by genomic sequencing, results indicated that genes related to the glutamate dependent difference mainly involved in carbohydrate transport and metabolism and amino acid metabolism, and 13 genes related to γ-PGA synthesis were mutated in GXG-5. This study provided a potential glutamate-independent strain to replace glutamate-dependent strain for γ-PGA production, and shared novel information for understanding the glutamate dependent difference at the genomic level.
Collapse
|
21
|
Feng J, Shi Q, Zhou G, Wang L, Chen A, Xie X, Huang X, Hu W. Improved production of poly-γ-glutamic acid with low molecular weight under high ferric ion concentration stress in Bacillus licheniformis ATCC 9945a. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.02.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
22
|
A novel soybean flour as a cryoprotectant in freeze-dried Bacillus subtilis SB-MYP-1. Lebensm Wiss Technol 2017. [DOI: 10.1016/j.lwt.2016.11.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
23
|
Chen P, Yan L, Zhang S, Wu Z, Li S, Yan X, Wang N, Liang N, Li H. Optimizing bioconversion of ferulic acid to vanillin by Bacillus subtilis in the stirred packed reactor using Box-Behnken design and desirability function. Food Sci Biotechnol 2017; 26:143-152. [PMID: 30263521 DOI: 10.1007/s10068-017-0019-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 06/12/2016] [Accepted: 11/14/2016] [Indexed: 10/20/2022] Open
Abstract
A stirring bioreactor packed with a carbon fiber textiles (FT) biofilm formed by Bacillus subtilis was used to produce vanillin from ferulic acid. Biofilm formation was characterized by scanning electron microscopy. The interactive effects of three variables on vanillin molar yield (M) and conversion efficiency of ferulic acid (E) were evaluated by response surface methodology (RSM) with a Box-Behnken design (BBD). The optimal conversion conditions with a maximum overall desirability D of 0.983 were obtained by a desirability function. Considering the actual operation, the confirmation tests were performed using the slightly modified optimal conditions (initial ferulic acid concentration 1.55 g/L, temperature 35°C, stirring speed 220 rpm). The results showed that M and E were 57.42 and 93.53%, respectively. This was only 1.03% and 1.87%, respectively, different from the predicted values, confirming the validity of the predicted models. These revealed that the stirred packed reactor could be successfully used in vanillin bioconversion from ferulic acid.
Collapse
Affiliation(s)
- Peng Chen
- 1School of Pharmacy, Lanzhou University, Lanzhou, 730020 China
| | - Lei Yan
- 2College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319 China
| | - Shuang Zhang
- 2College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319 China
| | - Zhengrong Wu
- 1School of Pharmacy, Lanzhou University, Lanzhou, 730020 China
| | - Suyue Li
- Gansu Institute of Business and Technology, Lanzhou, 730010 China
| | - Xiaojuan Yan
- Gansu Institute of Business and Technology, Lanzhou, 730010 China
| | - Ningbo Wang
- Gansu Institute of Business and Technology, Lanzhou, 730010 China
| | - Ning Liang
- Gansu Institute of Business and Technology, Lanzhou, 730010 China
| | - Hongyu Li
- 1School of Pharmacy, Lanzhou University, Lanzhou, 730020 China
| |
Collapse
|
24
|
Sakamoto S, Kawase Y. Adsorption capacities of poly-γ-glutamic acid and its sodium salt for cesium removal from radioactive wastewaters. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 165:151-158. [PMID: 27723527 DOI: 10.1016/j.jenvrad.2016.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/03/2016] [Accepted: 10/03/2016] [Indexed: 05/22/2023]
Abstract
Cesium removal from radioactive wastewaters was examined using water-insoluble poly-γ-glutamic acid (γ-PGA) and water-soluble sodium salt form poly-γ-L-glutamic acid (γ-PGANa) as biosorbents. The maximum adsorption capacities at equilibrium of γ-PGA and γ-PGANa for Cs were 345 mg-Cs(g-γ-PGA)-1 at pH 6.0 and 290 mg-Cs(g-γ-PGANa)-1 at pH 9.0, respectively. At lower pH < pKa, the carboxyl groups of γ-PGA primarily remained in the protonated form and adsorption of Cs only slightly occurred. At higher pH > pKa, the adsorption of Cs was significantly facilitated due to ionization of carboxyl groups to carboxylate ion. Adsorption of Cs at pH > 9.0 was inhibited due to the hydrolysis of Cs. The Langmuir model could successfully describe the isotherm data. For γ-PGA and γ-PGANa, the maximum adsorption capacities at equilibrium in the Langmuir model were 446 and 333 mg-Cs(g-adsorbent)-1, respectively. The high adsorption capacities confirmed a potential utilization of γ-PGA and γ-PGANa for Cs removal. The adsorption of Cs by both γ-PGA and γ-PGANa attained the equilibrium within 0.5 min. The very quick equilibration is a benefit from the viewpoint of practical application. The spectra of FT-IR and XPS before and after adsorption confirmed the adsorption of Cs onto γ-PGA and γ-PGANa via electrostatic interaction with carboxylate anions.
Collapse
Affiliation(s)
- Shigeki Sakamoto
- Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan
| | - Yoshinori Kawase
- Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan.
| |
Collapse
|
25
|
Biotransformation of ferulic acid to vanillin in the packed bed-stirred fermentors. Sci Rep 2016; 6:34644. [PMID: 27708366 PMCID: PMC5052561 DOI: 10.1038/srep34644] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 09/14/2016] [Indexed: 11/26/2022] Open
Abstract
We performed the biotransformation of ferulic acid to vanillin using Bacillus subtilis (B. subtilis) in the stirring packed-bed reactors filled with carbon fiber textiles (CFT). Scanning electron microscope (SEM), HPLC, qRT-PCR and ATP assay indicated that vanillin biotransformation is tightly related to cell growth, cellar activity and the extent of biofilm formation. The biotransformation was affected by hydraulic retention time (HRT), temperature, initial pH, stirring speed and ferulic acid concentration, and the maximum vanillin production was obtained at 20 h, 35 °C, 9.0, 200 rpm, 1.5 g/L, respectively. Repeated batch biotransformation performed under this optimized condition showed that the maximum productivity (0.047 g/L/h) and molar yield (60.43%) achieved in immobilized cell system were 1.84 and 3.61 folds higher than those achieved in free cell system. Therefore, the stirring reactor packed with CFT carrier biofilm formed by B. subtilis represented a valid biocatalytic system for the production of vanillin.
Collapse
|
26
|
Zeng W, Chen G, Wu H, Wang J, Liu Y, Guo Y, Liang Z. Improvement of Bacillus subtilis for poly-γ-glutamic acid production by genome shuffling. Microb Biotechnol 2016; 9:824-833. [PMID: 27562078 PMCID: PMC5072198 DOI: 10.1111/1751-7915.12405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 07/18/2016] [Accepted: 07/24/2016] [Indexed: 12/03/2022] Open
Abstract
Poly‐γ‐glutamic acid (γ‐PGA) is a promising microbial polymer with potential applications in industry, agriculture and medicine. The use of high γ‐PGA‐producing strains is an effective approach to improve productivity of γ‐PGA. In this study, we developed a mutant, F3‐178, from Bacillus subtilis GXA‐28 using genome shuffling. The morphological characteristics of F3‐178 and GXA‐28 were not identical. Compared with GXA‐28 (18.4 ± 0.8 g l−1), the yield of γ‐PGA was 1.9‐fold higher in F3‐178 (34.3 ± 1.2 g l−1). Results from batch fermentation in 3.7 l fermenter showed that F3‐178 was satisfactory for industrial production of γ‐PGA. Metabolic studies suggested that the higher γ‐PGA yield in F3‐178 could be attributed to increased intracellular flux and uptake of extracellular glutamate. Real‐time PCR indicated that mRNA level of pgsB in F3‐178 was 18.8‐fold higher than in GXA‐28, suggesting the higher yield might be related to the overexpression of genes involved in γ‐PGA production. This study demonstrated that genome shuffling can be used for rapid improvement of γ‐PGA strains, and the possible mechanism for the improved phenotype was also explored at the metabolic and transcriptional levels.
Collapse
Affiliation(s)
- Wei Zeng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Guiguang Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Hao Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Jun Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Yanliao Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Ye Guo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Zhiqun Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China. .,Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning, Guangxi, 530004, China. .,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China.
| |
Collapse
|
27
|
Zeng W, Liang Z, Li Z, Bian Y, Li Z, Tang Z, Chen G. Regulation of poly-γ-glutamic acid production in Bacillus subtilis GXA-28 by potassium. J Taiwan Inst Chem Eng 2016. [DOI: 10.1016/j.jtice.2015.12.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
28
|
Tang B, Zhang D, Li S, Xu Z, Feng X, Xu H. Enhanced poly(γ-glutamic acid) production by H 2 O 2 -induced reactive oxygen species in the fermentation of Bacillus subtilis NX-2. Biotechnol Appl Biochem 2015. [PMID: 26202728 DOI: 10.1002/bab.1416] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Effects of reactive oxygen species (ROS) on cell growth and poly(γ-glutamic acid) (γ-PGA) synthesis were studied by adding hydrogen peroxide to a medium of Bacillus subtilis NX-2. After optimizing the addition concentration and time of H2 O2 , a maximum concentration of 33.9 g/L γ-PGA was obtained by adding 100 µM H2 O2 to the medium after 24 H. This concentration was 20.6% higher than that of the control. The addition of diphenyleneiodonium chloride (ROS inhibitor) can interdict the effect of H2 O2 -induced ROS. Transcriptional levels of the cofactors and relevant genes were also determined under ROS stress to illustrate the possible metabolic mechanism contributing to the improve γ-PGA production. The transcriptional levels of genes belonging to the tricarboxylic acid cycle and electron transfer chain system were significantly increased by ROS, which decreased the NADH/NAD+ ratio and increased the ATP levels, thereby providing more reducing power and energy for γ-PGA biosynthesis. The enhanced γ-PGA synthetic genes also directly promoted the formation of γ-PGA. This study was the first to use the ROS control strategy for γ-PGA fermentation and provided valuable information on the possible mechanism by which ROS regulated γ-PGA biosynthesis in B. subtilis NX-2.
Collapse
Affiliation(s)
- Bao Tang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, People's Republic of China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, People's Republic of China
| | - Dan Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, People's Republic of China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, People's Republic of China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, People's Republic of China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, People's Republic of China
| | - Zongqi Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, People's Republic of China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, People's Republic of China
| | - Xiaohai Feng
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, People's Republic of China.
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, People's Republic of China.
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, People's Republic of China.
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, People's Republic of China.
| |
Collapse
|
29
|
Draft Genome Sequence of Bacillus subtilis GXA-28, a Thermophilic Strain with High Productivity of Poly-γ-Glutamic Acid. GENOME ANNOUNCEMENTS 2014; 2:2/6/e01259-14. [PMID: 25477413 PMCID: PMC4256194 DOI: 10.1128/genomea.01259-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Bacillus subtilis GXA-28 is a thermophilic strain that can produce high yield and high molecular weight of poly-γ-glutamic acid under high temperature. Here, we report the draft genome sequence of this strain, which may provide the genomic basis for the high productivity of poly-γ-glutamic acid.
Collapse
|