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Kataoka N. Ketogluconate production by Gluconobacter strains: enzymes and biotechnological applications. Biosci Biotechnol Biochem 2024; 88:499-508. [PMID: 38323387 DOI: 10.1093/bbb/zbae013] [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: 12/26/2023] [Accepted: 02/01/2024] [Indexed: 02/08/2024]
Abstract
Gluconobacter strains perform incomplete oxidation of various sugars and alcohols, employing regio- and stereoselective membrane-bound dehydrogenases oriented toward the periplasmic space. This oxidative fermentation process is utilized industrially. The ketogluconate production pathway, characteristic of these strains, begins with the conversion of d-glucose to d-gluconate, which then diverges and splits into 2 pathways producing 5-keto-d-gluconate and 2-keto-d-gluconate and subsequently 2,5-diketo-d-gluconate. These transformations are facilitated by membrane-bound d-glucose dehydrogenase, glycerol dehydrogenase, d-gluconate dehydrogenase, and 2-keto-d-gluconate dehydrogenase. The variance in end products across Gluconobacter strains stems from the diversity of enzymes and their activities. This review synthesizes biochemical and genetic knowledge with biotechnological applications, highlighting recent advances in metabolic engineering and the development of an efficient production process focusing on enzymes relevant to the ketogluconate production pathway in Gluconobacter strains.
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Affiliation(s)
- Naoya Kataoka
- Organization for Research Initiatives, Yamaguchi University, Yamaguchi, Japan
- Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan
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Kataoka N, Naoki K, Ano Y, Matsushita K, Yakushi T. Development of efficient 5-ketogluconate production system by Gluconobacter japonicus. Appl Microbiol Biotechnol 2022; 106:7751-7761. [PMID: 36271931 DOI: 10.1007/s00253-022-12242-0] [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: 05/05/2022] [Revised: 09/08/2022] [Accepted: 10/12/2022] [Indexed: 11/02/2022]
Abstract
5-Ketogluconate (5KGA) is a precursor for synthesizing tartrate, a valuable compound used in several industries. In a previous study, Gluconobacter japonicus NBRC 3271 mutant strain D2, which lacks two membranous gluconate 2-dehydrogenases, was shown to produce 5KGA but not 2-ketogluconate from a mixture of glucose and gluconate. In this study, we aimed to develop an efficient 5KGA production system using G. japonicus D2 as the parental strain. D2 produced 5KGA from glucose in a jar fermentor culture; however, 5KGA levels were reduced during the late phase of cultivation. To increase the potential of D2 for 5KGA production, the cytoplasmic metabolism related to the utilization of 5KGA and gluconate was modified; the gno and gntK genes encoding 5KGA reductase and gluconokinase, respectively, were deleted from D2, generating D4. Improved 5KGA production was observed in D4 compared to that in D2, but a significant amount of gluconate remained at the end of cultivation, leading to an unsatisfied yield of 0.83 mol (mol glucose)-1. The conversion of gluconate to 5KGA is catalyzed by pyrroloquinoline quinone (PQQ)-dependent glycerol dehydrogenase (GLDH), which easily forms an apoenzyme by releasing PQQ and calcium ions. Thus, the effects of CaCl2 addition to the culture medium on 5KGA production by D4 were investigated. We demonstrated that 1 mM CaCl2 addition positively affected the maintenance of the PQQ-GLDH activity toward gluconate and consequently enhanced 5KGA production, and the yield reached 0.97 mol (mol glucose)-1. KEY POINTS: • An efficient 5KGA production system was developed with Gluconobacter japonicus. • Deleting the gno and gntK genes blocked the catabolism of 5KGA and gluconate. • The addition of 1 mM CaCl2 efficiently improved the conversion of glucose to 5KGA.
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Affiliation(s)
- Naoya Kataoka
- Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan. .,Department of Biological Science, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan. .,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan.
| | - Kotone Naoki
- Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Yoshitaka Ano
- Department of Bioscience, Graduate School of Agriculture, Ehime University, Matsuyama, Japan
| | - Kazunobu Matsushita
- Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.,Department of Biological Science, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan
| | - Toshiharu Yakushi
- Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.,Department of Biological Science, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan
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da Silva GAR, Oliveira SSDS, Lima SF, do Nascimento RP, Baptista ARDS, Fiaux SB. The industrial versatility of Gluconobacter oxydans: current applications and future perspectives. World J Microbiol Biotechnol 2022; 38:134. [PMID: 35688964 PMCID: PMC9187504 DOI: 10.1007/s11274-022-03310-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 05/13/2022] [Indexed: 11/26/2022]
Abstract
Gluconobacter oxydans is a well-known acetic acid bacterium that has long been applied in the biotechnological industry. Its extraordinary capacity to oxidize a variety of sugars, polyols, and alcohols into acids, aldehydes, and ketones is advantageous for the production of valuable compounds. Relevant G. oxydans industrial applications are in the manufacture of L-ascorbic acid (vitamin C), miglitol, gluconic acid and its derivatives, and dihydroxyacetone. Increasing efforts on improving these processes have been made in the last few years, especially by applying metabolic engineering. Thereby, a series of genes have been targeted to construct powerful recombinant strains to be used in optimized fermentation. Furthermore, low-cost feedstocks, mostly agro-industrial wastes or byproducts, have been investigated, to reduce processing costs and improve the sustainability of G. oxydans bioprocess. Nonetheless, further research is required mainly to make these raw materials feasible at the industrial scale. The current shortage of suitable genetic tools for metabolic engineering modifications in G. oxydans is another challenge to be overcome. This paper aims to give an overview of the most relevant industrial G. oxydans processes and the current strategies developed for their improvement.
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Affiliation(s)
- Gabrielle Alves Ribeiro da Silva
- Graduate Program in Science and Biotechnology, Biology Institute, Fluminense Federal University (UFF), Niterói-RJ, 24020-141, Brazil.
- Microbial Technology Laboratory, Pharmaceutical Technology Department, Faculty of Pharmacy, Fluminense Federal University (UFF), Niterói-RJ, 24241-000, Brazil.
- Ecology of Microbial Process Laboratory, Biochemical Engineering Department, Chemical School, Technology Center, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro-RJ, 21941-909, Brazil.
| | - Simone Santos de Sousa Oliveira
- Graduate Program in Science and Biotechnology, Biology Institute, Fluminense Federal University (UFF), Niterói-RJ, 24020-141, Brazil
- Microbial Technology Laboratory, Pharmaceutical Technology Department, Faculty of Pharmacy, Fluminense Federal University (UFF), Niterói-RJ, 24241-000, Brazil
| | - Sara Fernandes Lima
- Microbial Technology Laboratory, Pharmaceutical Technology Department, Faculty of Pharmacy, Fluminense Federal University (UFF), Niterói-RJ, 24241-000, Brazil
| | - Rodrigo Pires do Nascimento
- Ecology of Microbial Process Laboratory, Biochemical Engineering Department, Chemical School, Technology Center, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro-RJ, 21941-909, Brazil
| | - Andrea Regina de Souza Baptista
- Center for Microorganisms Investigation, Microbiology and Parasitology Department, Biomedical Institute, Fluminense Federal University (UFF), Niterói-RJ, 24020-141, Brazil
| | - Sorele Batista Fiaux
- Microbial Technology Laboratory, Pharmaceutical Technology Department, Faculty of Pharmacy, Fluminense Federal University (UFF), Niterói-RJ, 24241-000, Brazil
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Ma Y, Li B, Zhang X, Wang C, Chen W. Production of Gluconic Acid and Its Derivatives by Microbial Fermentation: Process Improvement Based on Integrated Routes. Front Bioeng Biotechnol 2022; 10:864787. [PMID: 35651548 PMCID: PMC9149244 DOI: 10.3389/fbioe.2022.864787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/14/2022] [Indexed: 11/13/2022] Open
Abstract
Gluconic acid (GA) and its derivatives, as multifunctional biological chassis compounds, have been widely used in the food, medicine, textile, beverage and construction industries. For the past few decades, the favored production means of GA and its derivatives are microbial fermentation using various carbon sources containing glucose hydrolysates due to high-yield GA production and mature fermentation processes. Advancements in improving fermentation process are thriving which enable more efficient and economical industrial fermentation to produce GA and its derivatives, such as the replacement of carbon sources with agro-industrial byproducts and integrated routes involving genetically modified strains, cascade hydrolysis or micro- and nanofiltration in a membrane unit. These efforts pave the way for cheaper industrial fermentation process of GA and its derivatives, which would expand the application and widen the market of them. This review summarizes the recent advances, points out the existing challenges and provides an outlook on future development regarding the production of GA and its derivatives by microbial fermentation, aiming to promote the combination of innovative production of GA and its derivatives with industrial fermentation in practice.
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Affiliation(s)
- Yan Ma
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Bing Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Xinyue Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Chao Wang
- Dongcheng District Center for Disease Control and Prevention, Beijing, China
- *Correspondence: Chao Wang, ; Wei Chen,
| | - Wei Chen
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- *Correspondence: Chao Wang, ; Wei Chen,
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Dai L, Jiang W, Jia R, Zhou X, Xu Y. Directional enhancement of 2-keto-gluconic acid production from enzymatic hydrolysate by acetic acid-mediated bio-oxidation with Gluconobacter oxydans. BIORESOURCE TECHNOLOGY 2022; 348:126811. [PMID: 35131459 DOI: 10.1016/j.biortech.2022.126811] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/30/2022] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
An acetic acid-mediated bio-oxidation strategy with Gluconobacter oxydans was developed to produce valuable 2-ketogluconic acid from lignocellulosic biomass. Metabolically, glucose is firstly oxidized to gluconic acid and further oxidized to 2-keto-gluconic acid by Gluconobacter oxydans. As a specific inhibitor for microbial fermentation generated from pretreatment, acetic acid was validated to have a down-regulated effect on bio-oxidizing glucose to gluconic acid. Nevertheless, it significantly facilitated 2-keto-gluconic acid accumulation and improved gluconate dehydrogenase activity. In the presence of 5.0 g/L acetic acid, the yield of 2-keto-gluconic acid increased from 38.0% to 80.5% using pure glucose as feedstock with 1.5 g/L cell loading. Meanwhile, 44.6 g/L 2-keto-gluconic acid with a yield of 83.5% was also achieved from the enzymatic hydrolysate. 2-keto-gluconic acid production, found in this study, laid a theoretical foundation for the industrial production of 2-keto-gluconic acid by Gluconobacter oxydans using lignocellulosic materials.
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Affiliation(s)
- Lin Dai
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Wenfei Jiang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Runqian Jia
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China
| | - Xin Zhou
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China.
| | - Yong Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
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He T, Xu C, Ding C, Liu X, Gu X. Optimization of Specific Productivity for Xylonic Acid Production by Gluconobacter oxydans Using Response Surface Methodology. Front Bioeng Biotechnol 2021; 9:729988. [PMID: 34485263 PMCID: PMC8414524 DOI: 10.3389/fbioe.2021.729988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
Large amounts of xylose cannot be efficiently metabolized and fermented due to strain limitations in lignocellulosic biorefinery. The conversion of xylose into high value chemicals can help to reduce the cost of commercialization. Therefore, xylonic acid with potential value in the construction industry offers a valuable alternative for xylose biorefinery. However, low productivity is the main challenge for xylonic acid fermentation. This study investigated the effect of three reaction parameters (agitation, aeration, and biomass concentration) on xylose acid production and optimized the key process parameters using response surface methodology The second order polynomial model was able to fit the experimental data by using multiple regression analysis. The maximum specific productivity was achieved with a value of 6.64 ± 0.20 g gx−1 h−1 at the optimal process parameters (agitation speed 728 rpm, aeration rate 7 L min−1, and biomass concentration 1.11 g L−1). These results may help to improve the production efficiency during xylose acid biotransformation from xylose.
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Affiliation(s)
- Tao He
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing, China
| | - Chaozhong Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing, China
| | - Chenrong Ding
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing, China
| | - Xu Liu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing, China
| | - Xiaoli Gu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing, China
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Fricke PM, Klemm A, Bott M, Polen T. On the way toward regulatable expression systems in acetic acid bacteria: target gene expression and use cases. Appl Microbiol Biotechnol 2021; 105:3423-3456. [PMID: 33856535 PMCID: PMC8102297 DOI: 10.1007/s00253-021-11269-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/24/2021] [Accepted: 04/04/2021] [Indexed: 01/06/2023]
Abstract
Acetic acid bacteria (AAB) are valuable biocatalysts for which there is growing interest in understanding their basics including physiology and biochemistry. This is accompanied by growing demands for metabolic engineering of AAB to take advantage of their properties and to improve their biomanufacturing efficiencies. Controlled expression of target genes is key to fundamental and applied microbiological research. In order to get an overview of expression systems and their applications in AAB, we carried out a comprehensive literature search using the Web of Science Core Collection database. The Acetobacteraceae family currently comprises 49 genera. We found overall 6097 publications related to one or more AAB genera since 1973, when the first successful recombinant DNA experiments in Escherichia coli have been published. The use of plasmids in AAB began in 1985 and till today was reported for only nine out of the 49 AAB genera currently described. We found at least five major expression plasmid lineages and a multitude of further expression plasmids, almost all enabling only constitutive target gene expression. Only recently, two regulatable expression systems became available for AAB, an N-acyl homoserine lactone (AHL)-inducible system for Komagataeibacter rhaeticus and an L-arabinose-inducible system for Gluconobacter oxydans. Thus, after 35 years of constitutive target gene expression in AAB, we now have the first regulatable expression systems for AAB in hand and further regulatable expression systems for AAB can be expected. KEY POINTS: • Literature search revealed developments and usage of expression systems in AAB. • Only recently 2 regulatable plasmid systems became available for only 2 AAB genera. • Further regulatable expression systems for AAB are in sight.
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Affiliation(s)
- Philipp Moritz Fricke
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Angelika Klemm
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Tino Polen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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Improvement of pyrroloquinoline quinone-dependent d-sorbitol dehydrogenase activity from Gluconobacter oxydans via expression of Vitreoscilla hemoglobin and regulation of dissolved oxygen tension for the biosynthesis of 6-(N-hydroxyethyl)-amino-6-deoxy-α-l-sorbofuranose. J Biosci Bioeng 2021; 131:518-524. [PMID: 33487552 DOI: 10.1016/j.jbiosc.2020.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 11/22/2022]
Abstract
The miglitol intermediate, 6-(N-hydroxyethyl)-amino-6-deoxy-α-l-sorbofuranose (6NSL), is catalyzed from N-2-hydroxyethyl glucamine (NHEG) by resting cells of Gluconobacter oxydans. One of the key factors limiting 6NSL production was the availability of oxygen during both cell cultivation and biotransformation of NHEG to 6NSL. Based on G. oxydans/pBBR1-sldAB-pqqABCDE-tldD (G. oxydans/AB-PQQ), the Vitreoscilla hemoglobin (VHb) was heterologously expressed in G. oxydans to enhance oxygen transfer efficiency and improve 6NSL production. The recombinant G. oxydans/AB-PQQ-VHb displayed higher biomass and NHEG oxidation activity than the control stain. The transcription levels of respiratory chain-related enzyme genes in G. oxydans/AB-PQQ-VHb exhibited up-regulation, indicating that the presence of VHb promoted the respiration. The dissolved oxygen (DO) concentration for cell cultivation was optimized in a 5-L stirred bioreactor. At a DO concentration of 20%, the maximum volumetric oxidation activity of NHEG of G. oxydans/AB-PQQ-VHb in the stirred bioreactor reached 168.3 ± 3.2 U/L. Furthermore, the biotransformation of NHEG to 6NSL using G. oxydans/AB-PQQ-VHb was carried out under different oxygen tensions to investigate the effect of oxygen on 6NSL production. Finally, up to 87.5 ± 5.9 g/L 6NSL was accumulated in the reaction mixture within 16 h when the DO was controlled at 30%.
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Efficient biosynthesis of 2-keto-D-gluconic acid by fed-batch culture of metabolically engineered Gluconobacter japonicus. Synth Syst Biotechnol 2019; 4:134-141. [PMID: 31384676 PMCID: PMC6661466 DOI: 10.1016/j.synbio.2019.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 11/25/2022] Open
Abstract
2-keto-d-gluconic acid (2-KGA) is a key precursor for synthesising vitamin C and isovitamin C. However, phage contamination is as constant problem in industrial production of 2-KGA using Pseudomonas fluorescens. Gluconobacter holds promise for producing 2-KGA due to impressive resistance to hypertonicity and acids, and high utilisation of glucose. In this study, the 2-KGA synthesis pathway was regulated to enhance production of 2-KGA and reduce accumulation of the by-products 5-keto-d-gluconic acid (5-KGA) and d-gluconic acid (D-GA) in the 2-KGA producer Gluconobacter japonicus CGMCC 1.49. Knocking out the ga5dh-1 gene from a competitive pathway and overexpressing the ga2dh-A gene from the 2-KGA synthesis pathway via homologous recombination increased the titre of 2-KGA by 63.81% in shake flasks. Additionally, accumulation of 5-KGA was decreased by 63.52% with the resulting G. japonicas-Δga5dh-1-ga2dh-A strain. Using an intermittent fed-batch mode in a 3 L fermenter, 2-KGA reached 235.3 g L−1 with a 91.1% glucose conversion rate. Scaling up in a 15 L fermenter led to stable 2-KGA titre with productivity of 2.99 g L−1 h−1, 11.99% higher than in the 3 L fermenter, and D-GA and 5-KGA by-products were completely converted to 2-KGA.
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10
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Zhou X, Zhou X, Xu Y. Improvement of fermentation performance of Gluconobacter oxydans by combination of enhanced oxygen mass transfer in compressed-oxygen-supplied sealed system and cell-recycle technique. BIORESOURCE TECHNOLOGY 2017; 244:1137-1141. [PMID: 28863996 DOI: 10.1016/j.biortech.2017.08.107] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 05/04/2023]
Abstract
Oxygen supply for microbial cultures is often identified as a limiting factor for aerobic fermentation. Through implementation of an integrated oxygen control strategy, the high oxygen mass transfer rate satisfied cellular metabolic demands. Gluconobacter oxydans NL71 fermentation of xylose to xylonic acid was improved remarkably. Finally, the productivity of xylonic acid from xylose by biooxidation was markedly increased to 32.5±3.1g/L/h compared to production levels using conventional laboratory-scale bioreactors. By improving microbial fermentative vitality, we successfully bio-converted 1800g xylose to 1813±36g xylonic acid by combination of a fed-batch addition of xylose substrate as well as a cell-recycling strategy. Bioconversion results demonstrated a highly efficient fermentation model that performs continuous bioreaction, assisting the effort to industrialize microbial xylonic acid production.
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Affiliation(s)
- Xin Zhou
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Xuelian Zhou
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Yong Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China.
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11
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Yuan J, Wu M, Lin J, Yang L. Combinatorial metabolic engineering of industrial Gluconobacter oxydans DSM2343 for boosting 5-keto-D-gluconic acid accumulation. BMC Biotechnol 2016; 16:42. [PMID: 27189063 PMCID: PMC4869267 DOI: 10.1186/s12896-016-0272-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
Background L-(+)-tartaric acid (L-TA) is an important organic acid, which is produced from the cream of tartar or stereospecific hydrolysis of the cis-epoxysuccinate. The former method is limited by the availability of raw material and the latter is dependent on the petrochemical material. Thus, new processes for the economical preparation of L-TA from carbohydrate or renewable resource would be much more attractive. Production of 5-keto-D-gluconate (5-KGA) from glucose by Gluconobacter oxydans is the first step to produce L-TA. The aim of this work is to enhance 5-KGA accumulation using combinatorial metabolic engineering strategies in G. oxydans. The sldAB gene, encoding sorbitol dehydrogenase, was overexpressed in an industrial strain G. oxydans ZJU2 under a carefully selected promoter, P0169. To enhance the efficiency of the oxidation by sldAB, the coenzyme pyrroloquinoline quinone (PQQ) and respiratory chain were engineered. Besides, the role in sldAB overexpression, coenzyme and respiratory chain engineering and their subsequent effects on 5-KGA production were investigated. Results An efficient, stable recombinant strain was constructed, whereas the 5-KGA production could be enhanced. By self-overexpressing the sldAB gene in G. oxydans ZJU2 under the constitutive promoter P0169, the resulting strain, G. oxydans ZJU3, produced 122.48 ± 0.41 g/L of 5-KGA. Furthermore, through the coenzyme and respiratory chain engineering, the titer and productivity of 5-KGA reached 144.52 ± 2.94 g/L and 2.26 g/(L · h), respectively, in a 15 L fermenter. It could be further improved the 5-KGA titer by 12.10 % through the fed-batch fermentation under the pH shift and dissolved oxygen tension (DOT) control condition, obtained 162 ± 2.12 g/L with the productivity of 2.53 g/(L · h) within 64 h. Conclusions The 5-KGA production could be significantly enhanced with the combinatorial metabolic engineering strategy in Gluconobacter strain, including sldAB overexpression, coenzyme and respiratory chain engineering. Fed-batch fermentation could further enlarge the positive effect and increase the 5-KGA production. All of these demonstrated that the robust recombinant strain can efficiently produce 5-KGA in larger scale to fulfill the industrial production of L-TA from 5-KGA.
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Affiliation(s)
- Jianfeng Yuan
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Mianbin Wu
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jianping Lin
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Lirong Yang
- Key Laboratory of Biomass Chemical Engineering of the Ministry of Education,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
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