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Tsigoriyna L, Arsov A, Gergov E, Petrova P, Petrov K. Influence of pH on Inulin Conversion to 2,3-Butanediol by Bacillus licheniformis 24: A Gene Expression Assay. Int J Mol Sci 2023; 24:14065. [PMID: 37762368 PMCID: PMC10531509 DOI: 10.3390/ijms241814065] [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: 08/20/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
2,3-Butanediol (2,3-BD) is an alcohol highly demanded in the chemical, pharmaceutical, and food industries. Its microbial production, safe non-pathogenic producer strains, and suitable substrates have been avidly sought in recent years. The present study investigated 2,3-BD synthesis by the GRAS Bacillus licheniformis 24 using chicory inulin as a cheap and renewable substrate. The process appears to be pH-dependent. At pH 5.25, the synthesis of 2,3-BD was barely detectable due to the lack of inulin hydrolysis. At pH 6.25, 2,3-BD concentration reached 67.5 g/L with rapid hydrolysis of the substrate but was accompanied by exopolysaccharide (EPS) synthesis. Since inulin conversion by bacteria is a complex process and begins with its hydrolysis, the question of the acting enzymes arose. Genome mining revealed that several glycoside hydrolase (GH) enzymes from different CAZy families are involved. Five genes encoding such enzymes in B. licheniformis 24 were amplified and sequenced: sacA, sacB, sacC, levB, and fruA. Real-time RT-PCR experiments showed that the process of inulin hydrolysis is regulated at the level of gene expression, as four genes were significantly overexpressed at pH 6.25. In contrast, the expression of levB remained at the same level at the different pH values at all-time points. It was concluded that the sacC and sacA/fruA genes are crucial for inulin hydrolysis. They encode exoinulinase (EC 3.2.1.80) and sucrases (EC 3.2.1.26), respectively. The striking overexpression of sacB under these conditions led to increased synthesis of EPS; therefore, the simultaneous production of 2,3-BD and EPS cannot be avoided.
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Affiliation(s)
- Lidia Tsigoriyna
- Institute of Chemical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Alexander Arsov
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (P.P.)
| | - Emanoel Gergov
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (P.P.)
| | - Penka Petrova
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (P.P.)
| | - Kaloyan Petrov
- Institute of Chemical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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High production of acetoin from glycerol by Bacillus subtilis 35. Appl Microbiol Biotechnol 2022; 107:175-185. [DOI: 10.1007/s00253-022-12301-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 12/05/2022]
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Abstract
The growing need for industrial production of bio-based acetoin and 2,3-butanediol (2,3-BD) is due to both environmental concerns, and their widespread use in the food, pharmaceutical, and chemical industries. Acetoin is a common spice added to many foods, but also a valuable reagent in many chemical syntheses. Similarly, 2,3-BD is an indispensable chemical on the platform in the production of synthetic rubber, printing inks, perfumes, antifreeze, and fuel additives. This state-of-the-art review focuses on representatives of the genus Bacillus as prospective producers of acetoin and 2,3-BD. They have the following important advantages: non-pathogenic nature, unpretentiousness to growing conditions, and the ability to utilize a huge number of substrates (glucose, sucrose, starch, cellulose, and inulin hydrolysates), sugars from the composition of lignocellulose (cellobiose, mannose, galactose, xylose, and arabinose), as well as waste glycerol. In addition, these strains can be improved by genetic engineering, and are amenable to process optimization. Bacillus spp. are among the best acetoin producers. They also synthesize 2,3-BD in titer and yield comparable to those of the pathogenic producers. However, Bacillus spp. show relatively lower productivity, which can be increased in the course of challenging future research.
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Highly Efficient 2,3-Butanediol Production by Bacillus licheniformis via Complex Optimization of Nutritional and Technological Parameters. FERMENTATION 2021. [DOI: 10.3390/fermentation7030118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
2,3-Butanediol (2,3-BD) is a reagent with remarkable commercial use as a platform chemical in numerous industries. The present study aims to determine the capabilities of non-pathogenic and cellulolytic Bacillus licheniformis 24 as a 2,3-BD producer. By applying the Plackett–Burman design and response surface methodology through central composite design (CCD), a complex optimization of medium and process parameters was conducted. Thus, among ten studied factors of medium content, four components were evaluated with a significant positive effect on 2,3-BD formation. Their optimal values for 2,3-BD production (yeast extract, 13.38 g/L; tryptone, 6.41 g/L; K2HPO4, 4.2 g/L; MgSO4, 0.32 g/L), as well as the optimal temperature (37.8 °C), pH (6.23) and aeration rate (3.68 vvm) were predicted by CCD experiments and validated in a series of batch processes. In optimized batch fermentation of 200 g/L of glucose 91.23 g/L of 2,3-BD was obtained, with the overall productivity of 1.94 g/L/h and yield of 0.488 g/g. To reveal the maximum 2,3-BD tolerance of B. licheniformis 24, fed-batch fermentation was carried out. The obtained 138.8 g/L of 2,3-BD with a yield of 0.479 g/g and productivity of 1.16 g/L/h ranks the strain among the best 2,3-BD producers.
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Wang D, Oh BR, Lee S, Kim DH, Joe MH. Process optimization for mass production of 2,3-butanediol by Bacillus subtilis CS13. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:15. [PMID: 33419471 PMCID: PMC7791975 DOI: 10.1186/s13068-020-01859-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/13/2020] [Indexed: 05/07/2023]
Abstract
BACKGROUND Bacillus subtilis CS13 was previously isolated for 2,3-butanediol (2,3-BD) and poly-γ-glutamic acid (γ-PGA) co-production. When culturing this strain without L-glutamic acid in the medium, 2,3-BD is the main metabolic product. 2,3-BD is an important substance and fuel with applications in the chemical, food, and pharmaceutical industries. However, the yield and productivity for the B. subtilis strain should be improved for more efficient production of 2,3-BD. RESULTS The medium composition, which contained 281.1 g/L sucrose, 21.9 g/L ammonium citrate, and 3.6 g/L MgSO4·7H2O, was optimized by response surface methodology for 2,3-BD production using B. subtilis CS13. The maximum amount of 2,3-BD (125.5 ± 3.1 g/L) was obtained from the optimized medium after 96 h. The highest concentration and productivity of 2,3-BD were achieved simultaneously at an agitation speed of 500 rpm and aeration rate of 2 L/min in the batch cultures. A total of 132.4 ± 4.4 g/L 2,3-BD was obtained with a productivity of 2.45 ± 0.08 g/L/h and yield of 0.45 g2,3-BD/gsucrose by fed-batch fermentation. The meso-2,3-BD/2,3-BD ratio of the 2,3-BD produced by B. subtilis CS13 was 92.1%. Furthermore, 89.6 ± 2.8 g/L 2,3-BD with a productivity of 2.13 ± 0.07 g/L/h and yield of 0.42 g2,3-BD/gsugar was achieved using molasses as a carbon source. CONCLUSIONS The production of 2,3-BD by B. subtilis CS13 showed a higher concentration, productivity, and yield compared to the reported generally recognized as safe 2,3-BD producers. These results suggest that B. subtilis CS13 is a promising strain for industrial-scale production of 2,3-BD.
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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
| | - Baek-Rock Oh
- Microbial Biotechnology Research Center, Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, 56212, 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.
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Conversion of Xylose from Birch Hemicellulose Hydrolysate to 2,3-Butanediol with Bacillus vallismortis. FERMENTATION-BASEL 2020. [DOI: 10.3390/fermentation6030086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Biotechnologically produced 2,3-butanediol (2,3-BDO) is a potential starting material for industrial bulk chemicals, such as butadiene or methyl ethyl ketone, which are currently produced from fossil feedstocks. So far, the highest 2,3-BDO concentrations have been obtained with risk class 2 microorganisms and pure glucose as substrate. However, as glucose stays in competition to food and feed industries, a lot of effort has been done in the last years finding efficient alternative substrates. Thereby xylose from hydrolysed wood hemicelluloses is a promising substrate for the production of 2,3-BDO. The risk class 1 microorganism Bacillus vallismortis strain was identified as a very promising 2,3-BDO producer. The strain is able to utilize xylose almost in the same manner as glucose. B. vallismortis is less prone to common inhibiting compounds in lignocellulosic extracts/hydrolysates. When using a concentrated hemicellulose fraction from birch wood hydrolysate, which was produced with ultrafiltration and after which the acetate concentration was reduced, a yield of 0.43 g g−1 was achieved and the xylose consumption and the 2,3-BDO production is basically the same as using pure xylose.
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Petrova P, Petlichka S, Petrov K. New Bacillus spp. with potential for 2,3-butanediol production from biomass. J Biosci Bioeng 2020; 130:20-28. [PMID: 32169317 DOI: 10.1016/j.jbiosc.2020.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/06/2019] [Accepted: 02/07/2020] [Indexed: 10/24/2022]
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Heyman B, Tulke H, Putri SP, Fukusaki E, Büchs J. Online monitoring of the respiratory quotient reveals metabolic phases during microaerobic 2,3-butanediol production with Bacillus licheniformis. Eng Life Sci 2020; 20:133-144. [PMID: 32874177 PMCID: PMC7447875 DOI: 10.1002/elsc.201900121] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/05/2019] [Accepted: 11/17/2019] [Indexed: 11/15/2022] Open
Abstract
Microaerobic cultivation conditions are often beneficial for the biotechnological production of reduced metabolites like 2,3-butanediol. However, due to oxygen limitation, process monitoring based on oxygen transfer rate, or dissolved oxygen measurement provides only limited information. In this study, online monitoring of the respiratory quotient is used to investigate the metabolic activity of Bacillus licheniformis DSM 8785 during mixed acid-2,3-butanediol production under microaerobic conditions. Thereby, the respiratory quotient provides valuable information about different metabolic phases. Based on partial reaction stoichiometries, the metabolic activity in each phase of the cultivation was revealed, explaining the course of the respiratory quotient. This provides profound information on the formation or consumption of glucose, 2,3-butanediol, ethanol and lactate, both, in shake flasks and stirred tank reactor cultivations. Furthermore, the average respiratory quotient correlates with the oxygen availability during the cultivation. Carbon mass balancing revealed that this reflects the increased formation of reduced metabolites with increasing oxygen limitation. The results clearly demonstrate that the respiratory quotient is a valuable online signal to reveal and understand the metabolic activity during microaerobic cultivations. The approach of combining respiratory quotient monitoring with stoichiometric considerations can be applied to other organisms and processes to define suitable cultivation conditions to produce the desired product spectrum.
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Affiliation(s)
- Benedikt Heyman
- AVT‐Biochemical EngineeringRWTH Aachen UniversityAachenGermany
| | - Hannah Tulke
- AVT‐Biochemical EngineeringRWTH Aachen UniversityAachenGermany
| | - Sastia Prama Putri
- Department of BiotechnologyGraduate School of EngineeringOsaka UniversityOsakaJapan
| | - Eiichiro Fukusaki
- Department of BiotechnologyGraduate School of EngineeringOsaka UniversityOsakaJapan
| | - Jochen Büchs
- AVT‐Biochemical EngineeringRWTH Aachen UniversityAachenGermany
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2,3-Butanediol production by the non-pathogenic bacterium Paenibacillus brasilensis. Appl Microbiol Biotechnol 2018; 102:8773-8782. [DOI: 10.1007/s00253-018-9312-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 07/09/2018] [Accepted: 08/07/2018] [Indexed: 11/26/2022]
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A Bibliometric Study of Scientific Publications regarding Hemicellulose Valorization during the 2000–2016 Period: Identification of Alternatives and Hot Topics. CHEMENGINEERING 2018. [DOI: 10.3390/chemengineering2010007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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