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Jin YH, Mah JH. Culture-dependent and -independent analyses of bacterial compositions and its contributions to formation of γ-aminobutyric acid and poly-γ-glutamic acid in Cheonggukjang. Food Res Int 2024; 179:114026. [PMID: 38342543 DOI: 10.1016/j.foodres.2024.114026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 02/13/2024]
Abstract
This study was performed to unveil bacterial compositions and their contributions to the formation of γ-aminobutyric acid (GABA) and poly-γ-glutamic acid (γ-PGA) in Cheonggukjang. To predict possible key factors contributing to the content of the bioactive compounds in Cheonggukjang, commercial products were analyzed for various parameters. The content of GABA and γ-PGA showed a negative (R2 = 0.61 - 0.73) and positive correlation (R2 = 0.53 - 0.96) with antioxidative activity. Consistently, GABA content showed a moderate negative correlation with γ-PGA content (R2 = 0.58). Among the physicochemical and microbial parameters, only salinity showed a moderate negative correlation with γ-PGA content (R2 = 0.75), which might be due to the inhibition of bacterial growth. It was also suggested that multiple factors (including bacterial species) were involved in the formation of GABA and γ-PGA in Cheonggukjang. To reveal dominant bacterial species and further presume their contributions to the bioactive compound formation in Cheonggukjang, both culture-independent (metagenomic) and -dependent (culturomic) methods were used. Culture-independent method showed that Bacillus piscis was dominant (23.37 - 94.89 %), followed by B. hisashii (0.00 - 62.45 %) and B. coagulans (0.00 - 13.82 %). Considering the quantitative speciation data on the bioactive compound content in Cheonggukjang (and bacterial production capability) together, it was further elucidated that B. piscis contributed primarily to the bioactive compound formation. Unlike this, culture-dependent analysis revealed that B. licheniformis and B. subtilis were dominant (30.0 - 47.6 and 17.5 - 39.5 %, respectively). Based on the quantitative speciation data on the bacterial production capability of GABA and γ-PGA, B. subtilis was the primarily contributing bacterial species to the bioactive compound formation. Consequently, it was observed that the bacterial compositions and their contributions to the bioactive compound formation determined by the two methods differed considerably, i.e., B. piscis and B. subtilis were identified to be prominent bacterial contributors, respectively, depending on the method used.
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Affiliation(s)
- Young Hun Jin
- Department of Food and Biotechnology, Korea University, Sejong 30019, Republic of Korea
| | - Jae-Hyung Mah
- Department of Food and Biotechnology, Korea University, Sejong 30019, Republic of Korea.
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Sakr EAE, Khater DZ, Kheiralla ZMH, El-Khatib KM. Statistical optimization of waste molasses-based exopolysaccharides and self-sustainable bioelectricity production for dual chamber microbial fuel cell by Bacillus piscis. Microb Cell Fact 2023; 22:202. [PMID: 37803422 PMCID: PMC10559494 DOI: 10.1186/s12934-023-02216-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/26/2023] [Indexed: 10/08/2023] Open
Abstract
BACKGROUND The application of exopolysaccharide-producing bacteria (EPS) in dual chamber microbial fuel cells (DCMFC) is critical which can minimize the chemical oxygen demand (COD) of molasses with bioelectricity production. Hence, our study aimed to evaluate the EPS production by the novel strain Bacillus piscis by using molasses waste. Therefore, statistical modeling was used to optimize the EPS production. Its structure was characterized by UV, FTIR, NMR, and monosaccharides compositions. Eventually, to highlight B. piscis' adaptability in energy applications, bioelectricity production by this organism was studied in the BCMFC fed by an optimized molasses medium. RESULTS B. piscis OK324045 characterized by 16S rRNA is a potent EPS-forming organism and yielded a 6.42-fold increase upon supplementation of molasses (5%), MgSO4 (0.05%), and inoculum size (4%). The novel exopolysaccharide produced by Bacillus sp. (EPS-BP5M) was confirmed by the structural analysis. The findings indicated that the MFC's maximum close circuit voltage (CCV) was 265 mV. The strain enhanced the performance of DCMFC achieving maximum power density (PD) of 31.98 mW m-2, COD removal rate of 90.91%, and color removal of 27.68%. Furthermore, cyclic voltammetry (CV) revealed that anodic biofilms may directly transfer electrons to anodes without the use of external redox mediators. Additionally, CV measurements made at various sweep scan rates to evaluate the kinetic studies showed that the electron charge transfer was irreversible. The SEM images showed the biofilm growth distributed over the electrode's surface. CONCLUSIONS This study offers a novel B. piscis strain for EPS-BP5M production, COD removal, decolorization, and electricity generation of the optimized molasses medium in MFCs. The biosynthesis of EPS-BP5M by a Bacillus piscis strain and its electrochemical activity has never been documented before. The approach adopted will provide significant benefits to sugar industries by generating bioelectricity using molasses as fuel and providing a viable way to improve molasses wastewater treatment.
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Affiliation(s)
- Ebtehag A E Sakr
- Botany Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, Egypt.
| | - Dena Z Khater
- Chemical Engineering and Pilot Plant Department, National Research Centre (NRC), El Buhouth St., Cairo, 12622, Dokki, Egypt
| | - Zeinab M H Kheiralla
- Botany Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, Egypt
| | - Kamel M El-Khatib
- Chemical Engineering and Pilot Plant Department, National Research Centre (NRC), El Buhouth St., Cairo, 12622, Dokki, Egypt
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Wang Z, Wu W, Cui L, Li X, Kulyar MFEA, Xiong H, Zhou N, Yin H, Li J, Li X. Isolation, characterization, and interaction of lignin-degrading bacteria from rumen of buffalo (Bubalus bubalis). J Basic Microbiol 2021; 61:757-768. [PMID: 34101885 DOI: 10.1002/jobm.202100068] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/06/2021] [Accepted: 05/28/2021] [Indexed: 11/10/2022]
Abstract
The purpose of this study was to isolate lignin-degrading bacteria from buffalo rumen and to explore their interactions further. Using lignin as the carbon source, three bacteria, B-04 (Ochrobactrum pseudintermedium), B-11 (Klebsiella pneumoniae), and B-45 (Bacillus sonorensis), which have shown lignin degradation potential, were successfully isolated and identified from the rumen fluid of buffalo by colony morphology, 16S ribosomal RNA gene sequencing, and biochemical and physiological analyses. The degradation rates of lignin were determined, and the maximum values were 4.86%, 11.1%, and 7.68% for B-04, B-11, and B-45, respectively. The maximum laccase activities were 0.65, 0.93, and 1.15 U/ml, while the maximum lignin peroxidase activities were 5.72, 8.29, and 18.69 U/ml, respectively. Pairwise interaction studies showed inhibitory interaction between B-04 and B-45, inhibitory interaction between B-04 and B-11, and symbiotic interaction between B-11 and B-45. This is the first report on the lignin degradation ability of bacteria isolated from the buffalo's rumen, which provides a new understanding for revealing the mechanism of roughage tolerance of buffalo.
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Affiliation(s)
- Zhen Wang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education; Department of Hubei Province Engineering Research Center in Buffalo Breeding and Products, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, PR China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China
| | - Wenqing Wu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China
| | - Luncheng Cui
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education; Department of Hubei Province Engineering Research Center in Buffalo Breeding and Products, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, PR China
| | - Xiang Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education; Department of Hubei Province Engineering Research Center in Buffalo Breeding and Products, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, PR China
| | | | - Haiqian Xiong
- Institute of Animal Husbandry, Huanggang Academy of Agricultural Sciences, Huanggang, Hubei, PR China
| | - Nian Zhou
- Institute of Animal Husbandry, Huanggang Academy of Agricultural Sciences, Huanggang, Hubei, PR China
| | - Huaihui Yin
- Institute of Animal Husbandry, Huanggang Academy of Agricultural Sciences, Huanggang, Hubei, PR China
| | - Jiakui Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, PR China
| | - Xiang Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education; Department of Hubei Province Engineering Research Center in Buffalo Breeding and Products, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, PR China
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