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Li F, Wang CY, Wu YC, Zhang MY, Wang YJ, Zhou XY, Zhang YX. Enhancing the biosynthesis of 2-keto-L-gulonic acid through multi-strategy metabolic engineering in Pseudomonas putida KT2440. BIORESOURCE TECHNOLOGY 2024; 392:130014. [PMID: 37956951 DOI: 10.1016/j.biortech.2023.130014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023]
Abstract
2-KGA, a precursor for the synthesis of Vitamin C, is currently produced in China utilizing the "two-step fermentation" technique. Nevertheless, this method exhibits many inherent constraints. This study presents a comprehensive metabolic engineering strategy to establish and optimize a one-step 2-KGA fermentation process from D-sorbitol in Pseudomonas putida KT2440. In general, the endogenous promoters were screened to identify promoter P1 for subsequent heterologous gene expression in KT2440. Following the screening and confirmation of suitable heterologous gene elements such as sldh, sdh, cytc551, pqqAB, and irrE, genetic recombination was performed in KT2440. In comparison to the initial achievement of expressing only sldh and sdh in KT2440, a yield of merely 0.42 g/L was obtained. However, by implementing four metabolic engineering strategies, the recombinant strain KT20 exhibited a significant enhancement in its ability to produce 2-KGA with a remarkable yield of up to 6.5 g/L - representing an impressive 15.48-fold improvement.
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Affiliation(s)
- Fan Li
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Cai-Yun Wang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Ying-Cai Wu
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Meng-Yue Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Yi-Jin Wang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Xun-Yong Zhou
- Sinobiotech (Shenzhen) Limited Company, Shenzhen 518001, People's Republic of China
| | - Yi-Xuan Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China.
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2
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Krüsemann JL, Rainaldi V, Cotton CA, Claassens NJ, Lindner SN. The cofactor challenge in synthetic methylotrophy: bioengineering and industrial applications. Curr Opin Biotechnol 2023; 82:102953. [PMID: 37320962 DOI: 10.1016/j.copbio.2023.102953] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/03/2023] [Accepted: 05/14/2023] [Indexed: 06/17/2023]
Abstract
Methanol is a promising feedstock for industrial bioproduction: it can be produced renewably and has high solubility and limited microbial toxicity. One of the key challenges for its bio-industrial application is the first enzymatic oxidation step to formaldehyde. This reaction is catalysed by methanol dehydrogenases (MDH) that can use NAD+, O2 or pyrroloquinoline quinone (PQQ) as an electron acceptor. While NAD-dependent MDH are simple to express and have the highest energetic efficiency, they exhibit mediocre kinetics and poor thermodynamics at ambient temperatures. O2-dependent methanol oxidases require high oxygen concentrations, do not conserve energy and thus produce excessive heat as well as toxic H2O2. PQQ-dependent MDH provide a good compromise between energy efficiency and good kinetics that support fast growth rates without any drawbacks for process engineering. Therefore, we argue that this enzyme class represents a promising solution for industry and outline engineering strategies for the implementation of these complex systems in heterologous hosts.
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Affiliation(s)
- Jan L Krüsemann
- Charité - Universitätsmedizin Berlin, Department of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany; Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany; Max Planck Institute for Terrestrial Microbiology, Department of Biochemistry and Synthetic Metabolism, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
| | - Vittorio Rainaldi
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | | | - Nico J Claassens
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Steffen N Lindner
- Charité - Universitätsmedizin Berlin, Department of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany; Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany.
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Identification of a Novel Dehydrogenase from Gluconobacter oxydans for Degradation of Inhibitors Derived from Lignocellulosic Biomass. FERMENTATION-BASEL 2023. [DOI: 10.3390/fermentation9030286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Inhibitors from lignocellulosic biomass have become the bottleneck of biorefinery development. Gluconobacter oxydans DSM2003 showed a high performance of inhibitors degradation, which had a short lag time in non-detoxified corn stover hydrolysate and could convert 90% of aldehyde inhibitors to weaker toxic acids. In this study, an aldehyde dehydrogenase gene W826-RS0111485, which plays an important function in the conversion of aldehyde inhibitors in Gluconobacter oxydans DSM2003, was identified. W826-RS0111485 was found by protein profiling, then a series of enzymatic properties were determined and were heterologously expressed in E. coli. The results indicated that NADP is the most suitable cofactor of the enzyme when aldehyde inhibitor is the substrate, and it had the highest oxidation activity to furfural among several aldehyde inhibitors. Under the optimal reaction conditions (50 °C, pH 7.5), the Km and Vmax of the enzyme under furfural stress were 2.45 and 80.97, respectively, and the Kcat was 232.22 min−1. The biodetoxification performance experiments showed that the recombinant E. coli containing the target gene completely converted 1 g/L furfural to furoic acid within 8 h, while the control E. coli only converted 18% furfural within 8 h. It was further demonstrated that W826-RS0111485 played an important role in the detoxification of furfural. The mining of this inhibitor degradation gene could provide a theoretical basis for rational modification of industrial strains to enhance its capacity of inhibitor degradation in the future.
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New perspectives into Gluconobacter-catalysed biotransformations. Biotechnol Adv 2023; 65:108127. [PMID: 36924811 DOI: 10.1016/j.biotechadv.2023.108127] [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: 10/22/2022] [Revised: 03/02/2023] [Accepted: 03/08/2023] [Indexed: 03/17/2023]
Abstract
Different from other aerobic microorganisms that oxidise carbon sources to water and carbon dioxide, Gluconobacter catalyses the incomplete oxidation of various substrates with regio- and stereoselectivity. This ability, as well as its capacity to release the resulting products into the reaction media, place Gluconobacter as a privileged member of a non-model microorganism class that may boost industrial biotechnology. Knowledge of new technologies applied to Gluconobacter has been piling up in recent years. Advancements in its genetic modification, application of immobilisation tools and careful designs of the transformations, have improved productivities and stabilities of Gluconobacter strains or enabled new bioconversions for the production of valuable marketable chemicals. In this work, the latest advancements applied to Gluconobacter-catalysed biotransformations are summarised with a special focus on recent available tools to improve them. From genetic and metabolic engineering to bioreactor design, the most recent works on the topic are analysed in depth to provide a comprehensive resource not only for scientists and technologists working on/with Gluconobacter, but for the general biotechnologist.
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Xu Y, Ji L, Xu S, Bilal M, Ehrenreich A, Deng Z, Cheng H. Membrane-bound sorbitol dehydrogenase is responsible for the unique oxidation of D-galactitol to L-xylo-3-hexulose and D-tagatose in Gluconobacter oxydans. Biochim Biophys Acta Gen Subj 2023; 1867:130289. [PMID: 36503080 DOI: 10.1016/j.bbagen.2022.130289] [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: 05/14/2022] [Revised: 11/27/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Gluconobacter oxydans, is used in biotechnology because of its ability to oxidize a wide variety of carbohydrates, alcohols, and polyols in a stereo- and regio-selective manner by membrane-bound dehydrogenases located in periplasmic space. These reactions obey the well-known Bertrand-Hudson's rule. In our previous study (BBA-General Subjects, 2021, 1865:129740), we discovered that Gluconobacter species, including G. oxydans and G. cerinus strain can regio-selectively oxidize the C-3 and C-5 hydroxyl groups of D-galactitol to rare sugars D-tagatose and L-xylo-3-hexulose, which represents an exception to Bertrand Hudson's rule. The enzyme catalyzing this reaction is located in periplasmic space or membrane-bound and is PQQ (pyrroloquinoline quinine) and Ca2+-dependent; we were encouraged to determine which type of enzyme(s) catalyze this unique reaction. METHODS Enzyme was identified by complementation of multi-deletion strain of Gluconobacter oxydans 621H with all putative membrane-bound dehydrogenase genes. RESULTS AND CONCLUSIONS In this study, we identified this gene encoding the membrane-bound PQQ-dependent dehydrogenase that catalyzes the unique galactitol oxidation reaction in its 3'-OH and 5'-OH. Complement experiments in multi-deletion G. oxydans BP.9 strains established that the enzyme mSLDH (encoded by GOX0855-0854, sldB-sldA) is responsible for galactitol's unique oxidation reaction. Additionally, we demonstrated that the small subunit SldB of mSLDH was membrane-bound and served as an anchor protein by fusing it to a red fluorescent protein (mRubby), and heterologously expressed in E. coli and the yeast Yarrowia lipolytica. The SldB subunit was required to maintain the holo-enzymatic activity that catalyzes the conversion of D-galactitol to L-xylo-3-hexulose and D-tagatose. The large subunit SldA encoded by GOX0854 was also characterized, and it was discovered that its 24 amino acids signal peptide is required for the dehydrogenation activity of the mSLDH protein. GENERAL SIGNIFICANCE In this study, the main membrane-bound polyol dehydrogenase mSLDH in G. oxydans 621H was proved to catalyze the unique galactitol oxidation, which represents an exception to the Bertrand Hudson's rule, and broadens its substrate ranges of mSLDH. Further deciphering the explicit enzymatic mechanism will prove this theory.
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Affiliation(s)
- Yirong Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Liyun Ji
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Shuo Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Muhammad Bilal
- Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60695 Poznan, Poland.
| | - Armin Ehrenreich
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Strasse, Freising, Germany.
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Hairong Cheng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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Fricke PM, Gries ML, Mürköster M, Höninger M, Gätgens J, Bott M, Polen T. The l-rhamnose-dependent regulator RhaS and its target promoters from Escherichia coli expand the genetic toolkit for regulatable gene expression in the acetic acid bacterium Gluconobacter oxydans. Front Microbiol 2022; 13:981767. [PMID: 36060754 PMCID: PMC9429829 DOI: 10.3389/fmicb.2022.981767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/13/2022] [Indexed: 11/25/2022] Open
Abstract
For regulatable target gene expression in the acetic acid bacterium (AAB) Gluconobacter oxydans only recently the first plasmids became available. These systems solely enable AraC- and TetR-dependent induction. In this study we showed that the l-rhamnose-dependent regulator RhaS from Escherichia coli and its target promoters PrhaBAD, PrhaT, and PrhaSR could also be used in G. oxydans for regulatable target gene expression. Interestingly, in contrast to the responsiveness in E. coli, in G. oxydans RhaS increased the expression from PrhaBAD in the absence of l-rhamnose and repressed PrhaBAD in the presence of l-rhamnose. Inserting an additional RhaS binding site directly downstream from the −10 region generating promoter variant PrhaBAD(+RhaS-BS) almost doubled the apparent RhaS-dependent promoter strength. Plasmid-based PrhaBAD and PrhaBAD(+RhaS-BS) activity could be reduced up to 90% by RhaS and l-rhamnose, while a genomic copy of PrhaBAD(+RhaS-BS) appeared fully repressed. The RhaS-dependent repression was largely tunable by l-rhamnose concentrations between 0% and only 0.3% (w/v). The RhaS-PrhaBAD and the RhaS-PrhaBAD(+RhaS-BS) systems represent the first heterologous repressible expression systems for G. oxydans. In contrast to PrhaBAD, the E. coli promoter PrhaT was almost inactive in the absence of RhaS. In the presence of RhaS, the PrhaT activity in the absence of l-rhamnose was weak, but could be induced up to 10-fold by addition of l-rhamnose, resulting in a moderate expression level. Therefore, the RhaS-PrhaT system could be suitable for tunable low-level expression of difficult enzymes or membrane proteins in G. oxydans. The insertion of an additional RhaS binding site directly downstream from the E. coli PrhaT −10 region increased the non-induced expression strength and reversed the regulation by RhaS and l-rhamnose from inducible to repressible. The PrhaSR promoter appeared to be positively auto-regulated by RhaS and this activation was increased by l-rhamnose. In summary, the interplay of the l-rhamnose-binding RhaS transcriptional regulator from E. coli with its target promoters PrhaBAD, PrhaT, PrhaSR and variants thereof provide new opportunities for regulatable gene expression in G. oxydans and possibly also for simultaneous l-rhamnose-triggered repression and activation of target genes, which is a highly interesting possibility in metabolic engineering approaches requiring redirection of carbon fluxes.
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Bertucci M, Ariano K, Zumsteg M, Schweiger P. Engineering a tunable bicistronic TetR autoregulation expression system in Gluconobacter oxydans. PeerJ 2022; 10:e13639. [PMID: 35873911 PMCID: PMC9306550 DOI: 10.7717/peerj.13639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 06/06/2022] [Indexed: 01/17/2023] Open
Abstract
Acetic acid bacteria are well-known for their ability to incompletely oxidize their carbon sources. Many of the products of these oxidations find industrial uses. Metabolic engineering of acetic acid bacteria would improve production efficiency and yield by allowing controllable gene expression. However, the molecular tools necessary for regulating gene expression have only recently started being explored. To this end the ability of the activation-dependent Plux system and two constitutive repression Ptet systems were examined for their ability to modulate gene expression in Gluconobacter oxydans. The activation-dependent Plux system increased gene expression approximately 5-fold regardless of the strength of the constitutive promoter used to express the luxR transcriptional activator. The Ptet system was tunable and had a nearly 20-fold induction when the tetR gene was expressed from the strong constitutive promoters P0169 and P264, but only had a 4-fold induction when a weak constitutive promoter (P452) was used for tetR expression. However, the Ptet system was somewhat leaky when uninduced. To mitigate this background activity, a bicistronic TetR expression system was constructed. Based on molecular modeling, this system is predicted to have low background activity when not induced with anhydrotetracycline. The bicistronic system was inducible up to >3,000-fold and was highly tunable with almost no background expression when uninduced, making this bicistronic system potentially useful for engineering G. oxydans and possibly other acetic acid bacteria. These expression systems add to the newly growing repertoire of suitable regulatable promoter systems in acetic acid bacteria.
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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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He Y, Xie Z, Zhang H, Liebl W, Toyama H, Chen F. Oxidative Fermentation of Acetic Acid Bacteria and Its Products. Front Microbiol 2022; 13:879246. [PMID: 35685922 PMCID: PMC9171043 DOI: 10.3389/fmicb.2022.879246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Acetic acid bacteria (AAB) are a group of Gram-negative, strictly aerobic bacteria, including 19 reported genera until 2021, which are widely found on the surface of flowers and fruits, or in traditionally fermented products. Many AAB strains have the great abilities to incompletely oxidize a large variety of carbohydrates, alcohols and related compounds to the corresponding products mainly including acetic acid, gluconic acid, gulonic acid, galactonic acid, sorbose, dihydroxyacetone and miglitol via the membrane-binding dehydrogenases, which is termed as AAB oxidative fermentation (AOF). Up to now, at least 86 AOF products have been reported in the literatures, but no any monograph or review of them has been published. In this review, at first, we briefly introduce the classification progress of AAB due to the rapid changes of AAB classification in recent years, then systematically describe the enzymes involved in AOF and classify the AOF products. Finally, we summarize the application of molecular biology technologies in AOF researches.
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Affiliation(s)
- Yating He
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhenzhen Xie
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Huan Zhang
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wolfgang Liebl
- Department of Microbiology, Technical University of Munich, Freising, Germany
| | - Hirohide Toyama
- Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Okinawa, Japan
| | - Fusheng Chen
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
- *Correspondence: Fusheng Chen
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The Roles of the Various Cellulose Biosynthesis Operons in Komagataeibacter hansenii ATCC 23769. Appl Environ Microbiol 2022; 88:e0246021. [PMID: 35319232 DOI: 10.1128/aem.02460-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cellulose is the most abundant biopolymer on earth and offers versatile applicability in biotechnology. Bacterial cellulose, especially, is an attractive material because it represents pure microcrystalline cellulose. The cellulose synthase complex of acetic acid bacteria serves as a model for general studies on (bacterial) cellulose synthesis. The genome of Komagataeibacter hansenii ATCC 23769 encodes three cellulose synthase (CS) operons of different sizes and gene compositions. This implies the question of which role each of the three CS-encoding operons, bcsAB1, bcsAB2, and bcsAB3, plays in overall cellulose synthesis. Therefore, we constructed markerless deletions in K. hansenii ATCC 23769, yielding mutant strains that expressed only one of the three CSs. Apparently, BcsAB1 is the only CS that produces fibers of crystalline cellulose. The markerless deletion of bcsAB1 resulted in a nonfiber phenotype in scanning electron microscopy analysis. Expression of the other CSs resulted in a different, nonfibrous extracellular polymeric substance (nfEPS) structure wrapping the cells, which is proposed to contain acetylated cellulose. Transcription analysis revealed that all CSs were expressed continuously and that bcsAB2 showed a higher transcription level than bcsAB1. Moreover, we were able to link the expression of diguanylate cyclase B (dgcB) to cellulose production. IMPORTANCE Acetic acid bacteria form a massive biofilm called "mother of vinegar," which is built of cellulose fibers. Bacterial cellulose is an appealing biomaterial with manifold applications in biomedicine and biotechnology. Because most cellulose-producing acetic acid bacteria express several cellulose synthase operons, a deeper understanding of their contribution to the synthesis of modified forms of cellulose fibers within a natural biofilm is of special interest. For the first time, we were able to identify the contribution of each of the three cellulose synthases to cellulose formation in Komagataeibacter hansenii ATCC 23769 after a chromosomal clean deletion. Moreover, we were able to depict their roles in spatial composition of the biofilm. These findings might be applicable in the future for naturally modified biomaterials with novel properties.
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Plekhanova Y, Tarasov S, Kitova A, Kolesov V, Kashin V, Sundramoorthy AK, Reshetilov A. Modification of thermally expanded graphite and its effect on the properties of the amperometric biosensor. 3 Biotech 2022; 12:42. [PMID: 35096499 PMCID: PMC8761185 DOI: 10.1007/s13205-021-03107-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/29/2021] [Indexed: 02/03/2023] Open
Abstract
The work considered the properties of a biosensor based on a novel nanomaterial-modified thermally expanded graphite (TEGM). The main focus was on whether the procedure of additional graphite thermal expansion would affect the electrochemical properties of biosensors based on membrane fractions of acetic acid bacteria Gluconobacter oxydans. Raman spectroscopy, scanning electron microscopy and electrochemical analysis were used for the study. Raman spectra showed that the formation of TEGM led to its stratification into smaller particles and a better orderly layered structure with high "graphenization" degree. Modification of TEG led to the formation of additional cavities into which bacterial cells or bacterial membrane fractions could be immobilized and affect the electrical conductivity of the biosensors positively. Calculation of the heterogeneous charge transfer constants showed that processes occurring on the electrodes are quasi-reversible. The limiting stage of these processes is the transfer of an electron from a biological component on the electrode surface, not the diffusion of the analyte from the solution to the active centers of the enzyme. We showed the possibility of developing third-generation mediator-free biosensors for glucose detection based on TEGM, as well as of second-generation mediator biosensors for glucose, ethanol and glycerol detection.
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Affiliation(s)
- Yulia Plekhanova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Pushchino Centre for Biological Research, Russian Academy of Sciences, 142290 Pushchino, Russian Federation
| | - Sergei Tarasov
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Pushchino Centre for Biological Research, Russian Academy of Sciences, 142290 Pushchino, Russian Federation
| | - Anna Kitova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Pushchino Centre for Biological Research, Russian Academy of Sciences, 142290 Pushchino, Russian Federation
| | - Vladimir Kolesov
- FSBIS V.A. Kotelnikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, 125009 Moscow, Russian Federation
| | - Vadim Kashin
- FSBIS V.A. Kotelnikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, 125009 Moscow, Russian Federation
| | - Ashok K. Sundramoorthy
- Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur, 603 203 Tamil Nadu India
| | - Anatoly Reshetilov
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Pushchino Centre for Biological Research, Russian Academy of Sciences, 142290 Pushchino, Russian Federation
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Yang H, Chen T, Wang M, Zhou J, Liebl W, Barja F, Chen F. Molecular biology: Fantastic toolkits to improve knowledge and application of acetic acid bacteria. Biotechnol Adv 2022; 58:107911. [PMID: 35033586 DOI: 10.1016/j.biotechadv.2022.107911] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/27/2021] [Accepted: 01/09/2022] [Indexed: 12/24/2022]
Abstract
Acetic acid bacteria (AAB) are a group of gram-negative, obligate aerobic bacteria within the Acetobacteraceae family of the alphaproteobacteria class, which are distributed in a wide variety of different natural sources that are rich in sugar and alcohols, as well as in several traditionally fermented foods. Their capabilities are not limited to the production of acetic acid and the brewing of vinegar, as their names suggest. They can also fix nitrogen and produce various kinds of aldehydes, ketones and other organic acids by incomplete oxidation (also referred to as oxidative fermentation) of the corresponding alcohols and/or sugars, as well as pigments and exopolysaccharides (EPS). In order to gain more insight into these organisms, molecular biology techniques have been extensively applied in almost all aspects of AAB research, including their identification and classification, acid resistance mechanisms, oxidative fermentation, EPS production, thermotolerance and so on. In this review, we mainly focus on the application of molecular biological technologies in the advancement of research into AAB while presenting the progress of the latest studies using these techniques.
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Affiliation(s)
- Haoran Yang
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, Hubei, China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Tao Chen
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, Hubei, China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Min Wang
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science &Technology, Tianjin, China
| | - Jingwen Zhou
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, Jiangsu, China
| | | | - François Barja
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland
| | - Fusheng Chen
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, Hubei, China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China.
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13
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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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14
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Fricke PM, Lürkens M, Hünnefeld M, Sonntag CK, Bott M, Davari MD, Polen T. Highly tunable TetR-dependent target gene expression in the acetic acid bacterium Gluconobacter oxydans. Appl Microbiol Biotechnol 2021; 105:6835-6852. [PMID: 34448898 PMCID: PMC8426231 DOI: 10.1007/s00253-021-11473-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 11/27/2022]
Abstract
Abstract For the acetic acid bacterium (AAB) Gluconobacter oxydans only recently the first tight system for regulatable target gene expression became available based on the heterologous repressor-activator protein AraC from Escherichia coli and the target promoter ParaBAD. In this study, we tested pure repressor-based TetR- and LacI-dependent target gene expression in G. oxydans by applying the same plasmid backbone and construction principles that we have used successfully for the araC-ParaBAD system. When using a pBBR1MCS-5-based plasmid, the non-induced basal expression of the Tn10-based TetR-dependent expression system was extremely low. This allowed calculated induction ratios of up to more than 3500-fold with the fluorescence reporter protein mNeonGreen (mNG). The induction was highly homogeneous and tunable by varying the anhydrotetracycline concentration from 10 to 200 ng/mL. The already strong reporter gene expression could be doubled by inserting the ribosome binding site AGGAGA into the 3’ region of the Ptet sequence upstream from mNG. Alternative plasmid constructs used as controls revealed a strong influence of transcription terminators and antibiotics resistance gene of the plasmid backbone on the resulting expression performance. In contrast to the TetR-Ptet-system, pBBR1MCS-5-based LacI-dependent expression from PlacUV5 always exhibited some non-induced basal reporter expression and was therefore tunable only up to 40-fold induction by IPTG. The leakiness of PlacUV5 when not induced was independent of potential read-through from the lacI promoter. Protein-DNA binding simulations for pH 7, 6, 5, and 4 by computational modeling of LacI, TetR, and AraC with DNA suggested a decreased DNA binding of LacI when pH is below 6, the latter possibly causing the leakiness of LacI-dependent systems hitherto tested in AAB. In summary, the expression performance of the pBBR1MCS-5-based TetR-Ptet system makes this system highly suitable for applications in G. oxydans and possibly in other AAB. Key Points • A pBBR1MCS-5-based TetR-Ptet system was tunable up to more than 3500-fold induction. • A pBBR1MCS-5-based LacI-PlacUV5 system was leaky and tunable only up to 40-fold. • Modeling of protein-DNA binding suggested decreased DNA binding of LacI at pH < 6. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-021-11473-x.
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Affiliation(s)
- Philipp Moritz Fricke
- Forschungszentrum Jülich GmbH, IBG-1: Biotechnology, Institute of Bio- and Geosciences, 52425 Jülich, Germany
| | - Martha Lürkens
- RWTH Aachen University, Institute of Biotechnology, Worringerweg 3, 52074 Aachen, Germany
| | - Max Hünnefeld
- Forschungszentrum Jülich GmbH, IBG-1: Biotechnology, Institute of Bio- and Geosciences, 52425 Jülich, Germany
| | - Christiane K. Sonntag
- Forschungszentrum Jülich GmbH, IBG-1: Biotechnology, Institute of Bio- and Geosciences, 52425 Jülich, Germany
| | - Michael Bott
- Forschungszentrum Jülich GmbH, IBG-1: Biotechnology, Institute of Bio- and Geosciences, 52425 Jülich, Germany
| | - Mehdi D. Davari
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle, Germany
| | - Tino Polen
- Forschungszentrum Jülich GmbH, IBG-1: Biotechnology, Institute of Bio- and Geosciences, 52425 Jülich, Germany
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15
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Sadler JC, Dennis JA, Johnson NW, Wallace S. Interfacing non-enzymatic catalysis with living microorganisms. RSC Chem Biol 2021; 2:1073-1083. [PMID: 34458824 PMCID: PMC8341791 DOI: 10.1039/d1cb00072a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/27/2021] [Indexed: 12/04/2022] Open
Abstract
Interfacing non-enzymatic catalysis with cellular metabolism is emerging as a powerful approach to produce a range of high value small molecules and polymers. In this review, we highlight recent examples from this promising young field. Specifically, we discuss demonstrations of living cells mediating redox processes for biopolymer production, interfacing solar-light driven chemistry with microbial metabolism, and intra- and extracellular non-enzymatic catalysis to generate high value molecules. This review highlights the vast potential of this nascent field to bridge the two disciplines of synthetic chemistry and synthetic biology for a sustainable chemical industry.
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Affiliation(s)
- Joanna C Sadler
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh Roger Land Building, Alexander Crum Brown Road, King's Buildings Edinburgh, EH9 3FF UK
| | - Jonathan A Dennis
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh Roger Land Building, Alexander Crum Brown Road, King's Buildings Edinburgh, EH9 3FF UK
- School of Chemistry, University of Edinburgh Joseph Black Building, David Brewster Road, King's Buildings Edinburgh, EH9 3F UK
| | - Nick W Johnson
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh Roger Land Building, Alexander Crum Brown Road, King's Buildings Edinburgh, EH9 3FF UK
| | - Stephen Wallace
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh Roger Land Building, Alexander Crum Brown Road, King's Buildings Edinburgh, EH9 3FF UK
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16
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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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17
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Chen Y, Liu L, Yu S, Li J, Zhou J, Chen J. Identification of Gradient Promoters of Gluconobacter oxydans and Their Applications in the Biosynthesis of 2-Keto-L-Gulonic Acid. Front Bioeng Biotechnol 2021; 9:673844. [PMID: 33898410 PMCID: PMC8064726 DOI: 10.3389/fbioe.2021.673844] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022] Open
Abstract
The acetic acid bacterium Gluconobacter oxydans is known for its unique incomplete oxidation and therefore widely applied in the industrial production of many compounds, e.g., 2-keto-L-gulonic acid (2-KLG), the direct precursor of vitamin C. However, few molecular tools are available for metabolically engineering G. oxydans, which greatly limit the strain development. Promoters are one of vital components to control and regulate gene expression at the transcriptional level for boosting production. In this study, the low activity of SDH was found to hamper the high yield of 2-KLG, and enhancing the expression of SDH was achieved by screening the suitable promoters based on RNA sequencing data. We obtained 97 promoters from G. oxydans’s genome, including two strong shuttle promoters and six strongest promoters. Among these promoters, P3022 and P0943 revealed strong activities in both Escherichia coli and G. oxydans, and the activity of the strongest promoter (P2703) was about threefold that of the other reported strong promoters of G. oxydans. These promoters were used to overexpress SDH in G. oxydans WSH-003. The titer of 2-KLG reached 3.7 g/L when SDH was under the control of strong promoters P2057 and P2703. This study obtained a series of gradient promoters, including two strong shuttle promoters, and expanded the toolbox of available promoters for the application in metabolic engineering of G. oxydans for high-value products.
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Affiliation(s)
- Yue Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China.,Science Center for Future Foods, Jiangnan University, Wuxi, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Li Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Shiqin Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China.,Science Center for Future Foods, Jiangnan University, Wuxi, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Jianghua Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China.,Science Center for Future Foods, Jiangnan University, Wuxi, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
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18
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Nguyen TM, Naoki K, Kataoka N, Matsutani M, Ano Y, Adachi O, Matsushita K, Yakushi T. Characterization of a cryptic, pyrroloquinoline quinone-dependent dehydrogenase of Gluconobacter sp. strain CHM43. Biosci Biotechnol Biochem 2021; 85:998-1004. [PMID: 33686415 DOI: 10.1093/bbb/zbab005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/25/2020] [Indexed: 11/13/2022]
Abstract
We characterized the pyrroloquinoline quinone (PQQ)-dependent dehydrogenase 9 (PQQ-DH9) of Gluconobacter sp. strain CHM43, which is a homolog of PQQ-dependent glycerol dehydrogenase (GLDH). We used a plasmid construct to express PQQ-DH9. The expression host was a derivative strain of CHM43, which lacked the genes for GLDH and the membrane-bound alcohol dehydrogenase and consequently had minimal ability to oxidize primary and secondary alcohols. The membranes of the transformant exhibited considerable d-arabitol dehydrogenase activity, whereas the reference strain did not, even if it had PQQ-DH9-encoding genes in the chromosome and harbored the empty vector. This suggests that PQQ-DH9 is not expressed in the genome. The activities of the membranes containing PQQ-DH9 and GLDH suggested that similar to GLDH, PQQ-DH9 oxidized a wide variety of secondary alcohols but had higher Michaelis constants than GLDH with regard to linear substrates such as glycerol. Cyclic substrates such as cis-1,2-cyclohexanediol were readily oxidized by PQQ-DH9.
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Affiliation(s)
- Thuy Minh Nguyen
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Kotone Naoki
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Naoya Kataoka
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.,Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan
| | - Minenosuke Matsutani
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Yoshitaka Ano
- Graduate School of Agriculture, Ehime University, Matsuyama, Japan
| | - Osao Adachi
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Kazunobu Matsushita
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.,Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan
| | - Toshiharu Yakushi
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.,Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, Japan
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19
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Miah R, Nina S, Murate T, Kataoka N, Matsutani M, Matsushita K, Yakushi T. Major aldehyde dehydrogenase AldFGH of Gluconacetobacter diazotrophicus is independent of pyrroloquinoline quinone but dependent on molybdopterin for acetic acid fermentation. Appl Microbiol Biotechnol 2021; 105:2341-2350. [PMID: 33591385 DOI: 10.1007/s00253-021-11144-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/12/2021] [Accepted: 01/26/2021] [Indexed: 11/28/2022]
Abstract
Acetic acid fermentation involves the oxidation of ethanol to acetic acid via acetaldehyde as the intermediate and is catalyzed by the membrane-bound alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) of acetic acid bacteria. Although ADH depends on pyrroloquinoline quinone (PQQ), the prosthetic group associated with ALDH remains a matter of debate. This study aimed to address the dependency of ALDH of Gluconacetobacter diazotrophicus strain PAL5 on PQQ and the physiological role of ALDH in acetic acid fermentation. We constructed deletion mutant strains for both the ALDH gene clusters of PAL5, aldFGH and aldSLC. In addition, the adhAB operon for ADH was eliminated, since it shows ALDH activity. The triple-deletion derivative ΔaldFGH ΔaldSLC ΔadhAB failed to show ALDH activity, which suggested that ALDH activity in PAL5 is derived from these three enzyme complexes. Since the single-gene cluster deletion derivative ΔaldFGH lost most ALDH activity, and accumulated much higher acetaldehyde than wild type under acetic acid fermentation conditions, we concluded that AldFGH functions as the major ALDH in PAL5. Furthermore, deletion of the PQQ biosynthesis gene cluster (pqqABCDE) abolished ADH activity completely, but did not affect ALDH activity. Instead, the molybdopterin biosynthesis gene deletion derivatives lost ALDH activity. Thus, we concluded that the AldFGH and AldSLC complexes of Ga. diazotrophicus PAL5 require a form of molybdopterin but not PQQ for ALDH activity. KEY POINTS: • AldFGH is the major aldehyde dehydrogenase in Gluconacetobacter diazotrophicus PAL5. • Acetaldehyde accumulated from ethanol in the absence of AldFGH. • Molybdopterin, rather than pyrroloquinoline quinone, is required for AldFGH.
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Affiliation(s)
- Roni Miah
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Shun Nina
- Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Takeru Murate
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Naoya Kataoka
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 753-8515, Japan.,Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Minenosuke Matsutani
- NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo, 156-8502, Japan
| | - Kazunobu Matsushita
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 753-8515, Japan.,Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515, Japan.,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Toshiharu Yakushi
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 753-8515, Japan. .,Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515, Japan. .,Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi, 753-8515, Japan.
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20
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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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21
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Fricke PM, Link T, Gätgens J, Sonntag C, Otto M, Bott M, Polen T. A tunable L-arabinose-inducible expression plasmid for the acetic acid bacterium Gluconobacter oxydans. Appl Microbiol Biotechnol 2020; 104:9267-9282. [PMID: 32974745 PMCID: PMC7567684 DOI: 10.1007/s00253-020-10905-4] [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: 08/01/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 01/21/2023]
Abstract
Abstract The acetic acid bacterium (AAB) Gluconobacter oxydans incompletely oxidizes a wide variety of carbohydrates and is therefore used industrially for oxidative biotransformations. For G. oxydans, no system was available that allows regulatable plasmid-based expression. We found that the l-arabinose-inducible PBAD promoter and the transcriptional regulator AraC from Escherichia coli MC4100 performed very well in G. oxydans. The respective pBBR1-based plasmids showed very low basal expression of the reporters β-glucuronidase and mNeonGreen, up to 480-fold induction with 1% l-arabinose, and tunability from 0.1 to 1% l-arabinose. In G. oxydans 621H, l-arabinose was oxidized by the membrane-bound glucose dehydrogenase, which is absent in the multi-deletion strain BP.6. Nevertheless, AraC-PBAD performed similar in both strains in the exponential phase, indicating that a gene knockout is not required for application of AraC-PBAD in wild-type G. oxydans strains. However, the oxidation product arabinonic acid strongly contributed to the acidification of the growth medium in 621H cultures during the stationary phase, which resulted in drastically decreased reporter activities in 621H (pH 3.3) but not in BP.6 cultures (pH 4.4). These activities could be strongly increased quickly solely by incubating stationary cells in d-mannitol-free medium adjusted to pH 6, indicating that the reporters were hardly degraded yet rather became inactive. In a pH-controlled bioreactor, these reporter activities remained high in the stationary phase (pH 6). Finally, we created a multiple cloning vector with araC-PBAD based on pBBR1MCS-5. Together, we demonstrated superior functionality and good tunability of an AraC-PBAD system in G. oxydans that could possibly also be used in other AAB. Key points • We found the AraC-PBADsystem from E. coli MC4100 was well tunable in G. oxydans. • In the absence of AraC orl-arabinose, expression from PBADwas extremely low. • This araC-PBADsystem could also be fully functional in other acetic acid bacteria. Electronic supplementary material The online version of this article (10.1007/s00253-020-10905-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Philipp Moritz Fricke
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Tobias Link
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Jochem Gätgens
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Christiane Sonntag
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Maike Otto
- 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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Liu D, Ke X, Hu ZC, Zheng YG. Combinational expression of D-sorbitol dehydrogenase and pyrroloquinoline quinone increases 6-(N-hydroxyethyl)-amino-6-deoxy-α-L-sorbofuranose production by Gluconobacter oxydans through cofactor manipulation. Enzyme Microb Technol 2020; 141:109670. [PMID: 33051020 DOI: 10.1016/j.enzmictec.2020.109670] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/21/2020] [Accepted: 09/10/2020] [Indexed: 11/29/2022]
Abstract
6-(N-hydroxyethyl)-amino-6-deoxy-l-sorbofuranose (6NSL), a key precursor in the synthesis of miglitol, is produced from N-2-hydroxyethyl-glucamine (NHEG) by the regioselective oxidation of Gluconobacter oxydans. The limitation of PQQ biosynthesis became a bottleneck for improvement of PQQ-dependent D-sorbitol dehydrogenase (mSLDH) activity. Five expression plasmids were constructed for the co-expression of the pqqABCDE gene cluster and the tldD gene on the basis of pBBR1-gHp0169-sldAB in G. oxydans to increase the biosynthesis of PQQ. The G. oxydans/pGA004, in which pqqABCDE and tldD were expressed as a cluster under the control of gHp0169 promoter, showed the optimal performance. The intracellular PQQ concentration and specific activity of mSLDH in cells increased by 79.3 % and 53.7 %, respectively, compared to that in G. oxydans/pBBR-sldAB. Then, the repeated batch biotransformation of NHEG to 6NSL by G. oxydans/pGA004 was carried out. Up to 75.0 ± 3.0 g/L of 6NSL production with 94.5 ± 3.6 % of average conversion rate of NHEG to 6NSL was achieved after four cycles of run. These results indicated that G. oxydans/pGA004 with high productivity had great potential for 6NSL production in industrial bioprocess.
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Affiliation(s)
- Dong Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Xia Ke
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Zhong-Ce Hu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China.
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
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Breeding of Gluconobacter oxydans with high PQQ-dependent D-sorbitol dehydrogenase for improvement of 6-(N-hydroxyethyl)-amino-6-deoxy-α-L-sorbofuranose production. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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24
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Hua X, Du G, Zhou X, Nawaz A, ul Haq I, Xu Y. A techno-practical method for overcoming the biotoxicity and volatility obstacles of butanol and butyric acid during whole-cell catalysis by Gluconobacter oxydans. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:102. [PMID: 32518590 PMCID: PMC7268751 DOI: 10.1186/s13068-020-01741-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Butyric acid is a platform chemical material, the production of which has been greatly stimulated by the diverse range of downstream applications in many industries. In particular, higher quality butyric acid used in food and medicine, is more dependent on microbiological production methods. Hence, the bio-oxidation of butanol to butyric acid has been identified as a promising method with good potential economic and environmental benefits. However, both butanol and butyric acid are usually intensively toxic to most microorganisms as well as the bio-oxidation pathway. To develop a green, efficient and competitive microbiological method is the primary work to overcome the bottleneck of butyric acid industry. RESULT A combined bioprocess was designed with alternative whole-cell catalysis for butyric acid bio-conversion from butanol by Gluconobacter oxydans in a sealed-oxygen supply bioreactor (SOS). In the operation system, the escape of volatile substrates and toxic chemicals to cells can be avoided by the use of a sealed bioreactor, combined with the rejuvenation of cells by supplying energy co-factors. Finally, during a one-batch whole-cell catalysis, the utilization rate of substrate increased from 56.6 to 96.0% by the simple skill. Additionally, the techno-practical bioprocess can realize the purpose of cell-recycling technology through the rejuvenation effect of co-factor. Finally, we obtained 135.3 g/L butyric acid and 216.7 g/L sorbose during a 60-h whole-cell catalysis. This techno-practical technology provides a promising approach to promote the industrial production of butyric acid with more competitiveness. CONCLUSION The techno-practical biotechnology has powerfully promoted the process of butyric acid production by microorganisms, especially makes up for the lack of aerobic fermentation in the industry, and surmounts the shortcomings of traditional anaerobic fermentation. At the same time, this technically practical system provides a promising approach for the promotion of the industrial production of butyric acid in a more competitive manner.
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Affiliation(s)
- Xia Hua
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, 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
| | - GenLai Du
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, 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
| | - Xin Zhou
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, 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
| | - Ali Nawaz
- Institute of Industrial Biotechnology, GC University, Lahore, 54000 Pakistan
| | - Ikram ul Haq
- Institute of Industrial Biotechnology, GC University, Lahore, 54000 Pakistan
| | - Yong Xu
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, No. 159 Longpan Road, 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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Hua X, Zhou X, Du G, Xu Y. Resolving the formidable barrier of oxygen transferring rate (OTR) in ultrahigh-titer bioconversion/biocatalysis by a sealed-oxygen supply biotechnology (SOS). BIOTECHNOLOGY FOR BIOFUELS 2020; 13:1. [PMID: 31911817 PMCID: PMC6942312 DOI: 10.1186/s13068-019-1642-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/22/2019] [Indexed: 05/18/2023]
Abstract
BACKGROUND The critical issue in the competitiveness between bioengineering and chemical engineering is the products titer and the volume productivity. The most direct and effective approach usually employs high-density biocatalyst, while the weakened mass transfer and evoked foam problem accompany ultrahigh-density biocatalyst loading and substrate/product titer. In high-density obligate aerobic bioconversion, oxygen as electron acceptor is a speed-limiting step in bioprocesses, but sufficient oxygen supply will lead to the foaming which results in a significant reduction in oxygen utilization and the use of additional defoamers. In this study, we designed a novel sealed-oxygen supply (SOS) biotechnology to resolve the formidable barrier of oxygen transferring rate (OTR), for bio-based fuels and chemical production process. RESULTS Based on systemic analysis of whole-cell catalysis in Gluconobacter oxydans, a novel sealed-oxygen supply technology was smartly designed and experimentally performed for biocatalytic oxidation of alcohols, sugars and so on. By a simple operation skill of automatic online supply of oxygen in a sealed stirring tank bioreactor of SOS, OTR barrier and foaming problem was resolved with great ease. We finally obtained ultrahigh-titer products of xylonic acid (XA), 3-hydroxypropionic acid (3-HPA), and erythrulose at 588.4 g/L, 69.4 g/L, and 364.7 g/L, respectively. Moreover, the volume productivity of three chemical products was improved by 150-250% compared with normal biotechnology. This SOS technology provides a promising approach to promote bioengineering competitiveness and advantages over chemical engineering. CONCLUSION SOS technology was demonstrated as an economic and universally applicable approach to bio-based fuels and chemicals production by whole-cell catalysis. The novel technology greatly promotes the competitiveness of bioengineering for chemical engineering, and provides a promising platform for the green and environmental use of biofuels.
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Affiliation(s)
- Xia Hua
- 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, No. 159 Longpan Road, 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
| | - 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, No. 159 Longpan Road, 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
| | - GenLai Du
- 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, No. 159 Longpan Road, 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, No. 159 Longpan Road, 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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Liu L, Zeng W, Du G, Chen J, Zhou J. Identification of NAD-Dependent Xylitol Dehydrogenase from Gluconobacter oxydans WSH-003. ACS OMEGA 2019; 4:15074-15080. [PMID: 31552350 PMCID: PMC6751703 DOI: 10.1021/acsomega.9b01867] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 08/20/2019] [Indexed: 05/08/2023]
Abstract
Gluconobacter oxydans plays an important role in the conversion of d-sorbitol to l-sorbose, which is an essential intermediate for the industrial-scale production of vitamin C. In the fermentation process, some d-sorbitol could be converted to d-fructose and other byproducts by uncertain dehydrogenases. Genome sequencing has revealed the presence of diverse genes encoding dehydrogenases in G. oxydans. However, the characteristics of most of these dehydrogenases remain unclear. Therefore, the analyses of these unknown dehydrogenases could be useful for identifying those related to the production of d-fructose and other byproducts. Accordingly, dehydrogenases in G. oxydans WSH-003, an industrial strain used for vitamin C production, were examined. A nicotinamide adenine dinucleotide (NAD)-dependent dehydrogenase, which was annotated as xylitol dehydrogenase 2, was identified, codon-optimized, and expressed in Escherichia coli BL21 (DE3) cells. The enzyme exhibited a high preference for NAD+ as the cofactor, while no activity with nicotinamide adenine dinucleotide phosphate, flavin adenine dinucleotide, or pyrroloquinoline quinone was noted. Although this enzyme presented high similarity with NAD-dependent xylitol dehydrogenase, it showed high activity to catalyze d-sorbitol to d-fructose. Unlike the optimum temperature and pH for most of the known NAD-dependent xylitol dehydrogenases (30-40 °C and about 6-8, respectively), those for the identified enzyme were 57 °C and 12, respectively. The values of K m and V max of the identified dehydrogenase toward l-sorbitol were 4.92 μM and 196.08 μM/min, respectively. Thus, xylitol dehydrogenase 2 can be useful for the cofactor-reduced nicotinamide adenine dinucleotide regeneration under alkaline conditions, or its knockout can improve the conversion ratio of d-sorbitol to l-sorbose.
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Affiliation(s)
- Li Liu
- School
of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry
of Education, National Engineering Laboratory for Cereal Fermentation Technology, The Key Laboratory of Carbohydrate
Chemistry and Biotechnology, Ministry of Education, and Jiangsu Provisional Research Center for
Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, Jiangsu, China
| | - Weizhu Zeng
- School
of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry
of Education, National Engineering Laboratory for Cereal Fermentation Technology, The Key Laboratory of Carbohydrate
Chemistry and Biotechnology, Ministry of Education, and Jiangsu Provisional Research Center for
Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, Jiangsu, China
| | - Guocheng Du
- School
of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry
of Education, National Engineering Laboratory for Cereal Fermentation Technology, The Key Laboratory of Carbohydrate
Chemistry and Biotechnology, Ministry of Education, and Jiangsu Provisional Research Center for
Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, Jiangsu, China
| | - Jian Chen
- School
of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry
of Education, National Engineering Laboratory for Cereal Fermentation Technology, The Key Laboratory of Carbohydrate
Chemistry and Biotechnology, Ministry of Education, and Jiangsu Provisional Research Center for
Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, Jiangsu, China
| | - Jingwen Zhou
- School
of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry
of Education, National Engineering Laboratory for Cereal Fermentation Technology, The Key Laboratory of Carbohydrate
Chemistry and Biotechnology, Ministry of Education, and Jiangsu Provisional Research Center for
Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, Jiangsu, China
- E-mail: . Tel/Fax: +86-510-85914317
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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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Overcoming NADPH product inhibition improves D-sorbitol conversion to L-sorbose. Sci Rep 2019; 9:815. [PMID: 30692560 PMCID: PMC6349845 DOI: 10.1038/s41598-018-37401-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 12/04/2018] [Indexed: 02/02/2023] Open
Abstract
Gluconobacter oxydans sorbitol dehydrogenase (GoSLDH) exhibits a higher catalytic efficiency than other l-sorbose producing enzymes. During the reaction catalysed by GoSLDH, NADP+ is reduced to NADPH and d-sorbitol is oxidized to l-sorbose. However, GoSLDH activity is inhibited by the NADPH (Ki = 100 μM) formed during the enzymatic reaction. Therefore, Escherichia coligosldh-lrenox producing both GoSLDH for d-sorbitol oxidation and LreNOX (NAD(P)H oxidase from Lactobacillus reuteri) for NADP+ regeneration was generated and used for l-sorbose production. Whole cell biocatalysts with the LreNOX cofactor recycling system showed a high conversion rate (92%) of d-sorbitol to l-sorbose in the presence of low concentration of NADP+ (0.5 mM). By alleviating NADPH accumulation during the catalytic reactions, E. coligosldh-lrenox exhibited 23-fold higher conversion rate of d-sorbitol than E. coligosldh. l-Sorbose production by E. coligosldh-lrenox reached 4.1 g/L after 40 min, which was 20.5-fold higher than that of E. coligosldh. We also constructed G. oxydansgosldh and G. oxydansgosldh-lrenox strains, and they exhibited 1.2- and 2.9-fold higher conversion rates than the wild-type G. oxydans KCTC 1091. The results indicate that overcoming NADPH product inhibition using LreNOX improves chemical production in NADP+-dependent enzymatic reactions.
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Valorization of Waste Glycerol to Dihydroxyacetone with Biocatalysts Obtained from Gluconobacter oxydans. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8122517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Waste glycerol is the main by-product generated during biodiesel production, in an amount reaching up to 10% of the produced biofuel. Is there any method which allows changing this waste into industrial valuable compounds? This manuscript describes a method for valorization of crude glycerol via microbial bioconversion. It has been shown that the use of free and immobilized biocatalysts obtained from Gluconobacter oxydans can enable beneficial valorization of crude glycerol to industrially valuable dihydroxyacetone. The highest concentration of this compound, reaching over 20 g·L−1, was obtained after 72 h of biotransformation with free G. oxydans cells, in a medium containing 30 or 50 g·L−1 of waste glycerol. Using a free cell extract resulted in higher concentrations of dihydroxyacetone and a higher valorization efficiency (up to 98%) compared to the reaction with an immobilized cell extract. Increasing waste glycerol concentration to 50 g·L−1 causes neither a faster nor higher increase in product yield and reaction efficiency compared to its initial concentration of 30 g·L−1. The proposed method could be an alternative for utilization of a petrochemical waste into industry applicated chemicals.
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30
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Kranz A, Steinmann A, Degner U, Mengus-Kaya A, Matamouros S, Bott M, Polen T. Global mRNA decay and 23S rRNA fragmentation in Gluconobacter oxydans 621H. BMC Genomics 2018; 19:753. [PMID: 30326828 PMCID: PMC6191907 DOI: 10.1186/s12864-018-5111-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 09/25/2018] [Indexed: 12/14/2022] Open
Abstract
Background Gluconobacter oxydans is a strictly aerobic Gram-negative acetic acid bacterium used industrially for oxidative biotransformations due to its exceptional type of catabolism. It incompletely oxidizes a wide variety of carbohydrates regio- and stereoselectively in the periplasm using membrane-bound dehydrogenases with accumulation of the products in the medium. As a consequence, only a small fraction of the carbon and energy source enters the cell, resulting in a low biomass yield. Additionally, central carbon metabolism is characterized by the absence of a functional glycolysis and absence of a functional tricarboxylic acid (TCA) cycle. Due to these features, G. oxydans is a highly interesting model organism. Here we analyzed global mRNA decay in G. oxydans to describe its characteristic features and to identify short-lived mRNAs representing potential bottlenecks in the metabolism for further growth improvement by metabolic engineering. Results Using DNA microarrays we estimated the mRNA half-lives in G. oxydans. Overall, the mRNA half-lives ranged mainly from 3 min to 25 min with a global mean of 5.7 min. The transcripts encoding GroES and GroEL required for proper protein folding ranked at the top among transcripts exhibiting both long half-lives and high abundance. The F-type H+-ATP synthase transcripts involved in energy metabolism ranked among the transcripts with the shortest mRNA half-lives. RNAseq analysis revealed low expression levels for genes of the incomplete TCA cycle and also the mRNA half-lives of several of those were short and below the global mean. The mRNA decay analysis also revealed an apparent instability of full-length 23S rRNA. Further analysis of the ribosome-associated rRNA revealed a 23S rRNA fragmentation pattern exhibiting new cleavage regions in 23S rRNAs which were previously not known. Conclusions The very short mRNA half-lives of the H+-ATP synthase, which is likely responsible for the ATP-proton motive force interconversion in G. oxydans under many or most conditions, is notably in contrast to mRNA decay data from other bacteria. Together with the short mRNA half-lives and low expression of some other central metabolic genes it could limit intended improvements of G. oxydans’ biomass yield by metabolic engineering. Also, further studies are needed to unravel the multistep process of the 23S rRNA fragmentation in G. oxydans. Electronic supplementary material The online version of this article (10.1186/s12864-018-5111-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Angela Kranz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,The Bioeconomy Science Center (BioSC), c/o Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Andrea Steinmann
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,The Bioeconomy Science Center (BioSC), c/o Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Ursula Degner
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Aliye Mengus-Kaya
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Susana Matamouros
- 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.,The Bioeconomy Science Center (BioSC), c/o Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Tino Polen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany. .,The Bioeconomy Science Center (BioSC), c/o Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
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31
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Yan J, Xu J, Cao M, Li Z, Xu C, Wang X, Yang C, Xu P, Gao C, Ma C. Engineering of glycerol utilization in Gluconobacter oxydans 621H for biocatalyst preparation in a low-cost way. Microb Cell Fact 2018; 17:158. [PMID: 30296949 PMCID: PMC6174558 DOI: 10.1186/s12934-018-1001-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
Background Whole cells of Gluconobacter oxydans are widely used in various biocatalytic processes. Sorbitol at high concentrations is commonly used in complex media to prepare biocatalysts. Exploiting an alternative process for preparation of biocatalysts with low cost substrates is of importance for industrial applications. Results G. oxydans 621H was confirmed to have the ability to grow in mineral salts medium with glycerol, an inevitable waste generated from industry of biofuels, as the sole carbon source. Based on the glycerol utilization mechanism elucidated in this study, the major polyol dehydrogenase (GOX0854) and the membrane-bound alcohol dehydrogenase (GOX1068) can competitively utilize glycerol but play no obvious roles in the biocatalyst preparation. Thus, the genes related to these two enzymes were deleted. Whole cells of G. oxydans ∆GOX1068∆GOX0854 can be prepared from glycerol with a 2.4-fold higher biomass yield than that of G. oxydans 621H. Using whole cells of G. oxydans ∆GOX1068∆GOX0854 as the biocatalyst, 61.6 g L−1 xylonate was produced from 58.4 g L−1 xylose at a yield of 1.05 g g−1. Conclusion This process is an example of efficient preparation of whole cells of G. oxydans with reduced cost. Besides xylonate production from xylose, other biocatalytic processes might also be developed using whole cells of metabolic engineered G. oxydans prepared from glycerol. Electronic supplementary material The online version of this article (10.1186/s12934-018-1001-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jinxin Yan
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Jing Xu
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China.,Dong Ying Oceanic and Fishery Bureau, 206 Yellow River Road, Dongying, 257091, People's Republic of China
| | - Menghao Cao
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Zhong Li
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Chengpeng Xu
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Xinyu Wang
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Chunyu Yang
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Chao Gao
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology & Shenzhen Research Institute, Shandong University, 27 Shanda South Road, Jinan, 250100, People's Republic of China.
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32
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Pyrroloquinoline quinone-dependent dehydrogenases of acetic acid bacteria. Appl Microbiol Biotechnol 2018; 102:9531-9540. [PMID: 30218379 DOI: 10.1007/s00253-018-9360-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/30/2018] [Accepted: 08/31/2018] [Indexed: 10/28/2022]
Abstract
Pyrroloquinoline quinone (PQQ)-dependent dehydrogenases (quinoproteins) of acetic acid bacteria (AAB), such as the membrane-bound alcohol dehydrogenase (ADH) and the membrane-bound glucose dehydrogenase, contain PQQ as the prosthetic group. Most of them are located on the periplasmic surface of the cytoplasmic membrane, and function as primary dehydrogenases in cognate substance-oxidizing respiratory chains. Here, we have provided an overview on the function and molecular architecture of AAB quinoproteins, which can be categorized into six groups according to the primary amino acid sequences. Based on the genomic data, we discuss the types of quinoproteins found in AAB genome and how they are distributed. Our analyses indicate that a significant number of uncharacterized orphan quinoproteins are present in AAB. By reviewing recent experimental developments, we discuss how to characterize the as-yet-unknown enzymes. Moreover, our bioinformatics studies also provide insights on how quinoproteins have developed into intricate enzymes. ADH comprises at least two subunits: the quinoprotein dehydrogenase subunit encoded by adhA and the cytochrome subunit encoded by adhB, and the genes are located in a polycistronic transcriptional unit. Findings on stand-alone derivatives of adhA encourage us to speculate on a possible route for ADH development in the evolutional history of AAB. A combination of bioinformatics studies on big genome sequencing data and wet studies assisted with genetic engineering would unravel biochemical functions and physiological role of uncharacterized quinoproteins in AAB, or even in unculturable metagenome.
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Herweg E, Schöpping M, Rohr K, Siemen A, Frank O, Hofmann T, Deppenmeier U, Büchs J. Production of the potential sweetener 5-ketofructose from fructose in fed-batch cultivation with Gluconobacter oxydans. BIORESOURCE TECHNOLOGY 2018; 259:164-172. [PMID: 29550669 DOI: 10.1016/j.biortech.2018.03.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/05/2018] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
Sweeteners improve the dietary properties of many foods. A candidate for a new natural sweetener is 5-ketofructose. In this study a fed-batch process for the production of 5-ketofructose was developed. A Gluconobacter oxydans strain overexpressing a fructose dehydrogenase from G. japonicus was used and the sensory properties of 5-ketofructose were analyzed. The compound showed an identical sweet taste quality as fructose and a similar intrinsic sweet threshold concentration of 16.4 mmol/L. The production of 5-ketofructose was characterized online by monitoring of the respiration activity in shake flasks. Pulsed and continuous fructose feeding was realized in 2 L stirred tank reactors and maximum fructose consumption rates were determined. 5-Ketofructose concentrations of up to 489 g/L, product yields up to 0.98 g5-KF/gfructose and space time yields up to 8.2 g/L/h were reached highlighting the potential of the presented process.
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Affiliation(s)
- Elena Herweg
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, 52074 Aachen, Germany; Bioeconomy Science Center (BioSC), Germany
| | - Marie Schöpping
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, 52074 Aachen, Germany; Bioeconomy Science Center (BioSC), Germany
| | - Katja Rohr
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, 52074 Aachen, Germany; Bioeconomy Science Center (BioSC), Germany
| | - Anna Siemen
- Bioeconomy Science Center (BioSC), Germany; Institute of Microbiology and Biotechnology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany
| | - Oliver Frank
- Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München, Lise-Meitner-Strasse 34, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular and Sensory Science, Technische Universität München, Lise-Meitner-Strasse 34, 85354 Freising, Germany
| | - Uwe Deppenmeier
- Bioeconomy Science Center (BioSC), Germany; Institute of Microbiology and Biotechnology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany
| | - Jochen Büchs
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, 52074 Aachen, Germany; Bioeconomy Science Center (BioSC), Germany.
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34
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Aldopentoses as new substrates for the membrane-bound, pyrroloquinoline quinone-dependent glycerol (polyol) dehydrogenase of Gluconobacter sp. Appl Microbiol Biotechnol 2018; 102:3159-3171. [PMID: 29468297 DOI: 10.1007/s00253-018-8848-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/22/2018] [Accepted: 02/08/2018] [Indexed: 01/14/2023]
Abstract
Membrane-bound, pyrroloquinoline quinone (PQQ)-dependent glycerol dehydrogenase (GLDH, or polyol dehydrogenase) of Gluconobacter sp. oxidizes various secondary alcohols to produce the corresponding ketones, such as oxidation of D-sorbitol to L-sorbose in vitamin C production. Substrate specificity of GLDH is considered limited to secondary alcohols in the D-erythro configuration at the next to the last carbon. Here, we suggest that L-ribose, D- and L-lyxoses, and L-tagatose are also substrates of GLDH, but these sugars do not meet the substrate specificity rule of GLDH. The oxygen consumption activity of wild-type Gluconobacter frateurii cell membranes depends on several kinds of sugars as compared with that of the membranes of a GLDH-negative variant. Biotransformation of those sugars with the membranes was examined to determine the reaction products. A time course measuring the pH in the reaction mixture and the increase or decrease in substrates and products on TLC suggested that oxidation products of L-lyxose and L-tagatose were ketones with unknown structures, but those of L-ribose and D-lyxose were acids. The oxidation product of L-ribose was purified and revealed to be L-ribonate by HRMS and NMR analysis. Biotransformation of L-ribose with the membranes and also with the whole cells produced L-ribonate in nearly stoichiometric amounts, indicating that the specific oxidation site in L-ribose is recognized by GLDH. Since purified GLDH produced L-ribonate without any intermediate-like compounds, we propose here a reaction model where the first carbon in the pyranose form of L-ribose is oxidized by GLDH to L-ribonolactone, which is further hydrolyzed spontaneously to produce L-ribonate.
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35
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RNAseq analysis of α-proteobacterium Gluconobacter oxydans 621H. BMC Genomics 2018; 19:24. [PMID: 29304737 PMCID: PMC5756330 DOI: 10.1186/s12864-017-4415-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 12/22/2017] [Indexed: 01/05/2023] Open
Abstract
Background The acetic acid bacterium Gluconobacter oxydans 621H is characterized by its exceptional ability to incompletely oxidize a great variety of carbohydrates in the periplasm. The metabolism of this α-proteobacterium has been characterized to some extent, yet little is known about its transcriptomes and related data. In this study, we applied two different RNAseq approaches. Primary transcriptomes enriched for 5′-ends of transcripts were sequenced to detect transcription start sites, which allow subsequent analysis of promoter motifs, ribosome binding sites, and 5´-UTRs. Whole transcriptomes were sequenced to identify expressed genes and operon structures. Results Sequencing of primary transcriptomes of G. oxydans revealed 2449 TSSs, which were classified according to their genomic context followed by identification of promoter and ribosome binding site motifs, analysis of 5´-UTRs including validation of predicted cis-regulatory elements and correction of start codons. 1144 (41%) of all genes were found to be expressed monocistronically, whereas 1634 genes were organized in 571 operons. Together, TSSs and whole transcriptome data were also used to identify novel intergenic (18), intragenic (328), and antisense transcripts (313). Conclusions This study provides deep insights into the transcriptional landscapes of G. oxydans. The comprehensive transcriptome data, which we made publicly available, facilitate further analysis of promoters and other regulatory elements. This will support future approaches for rational strain development and targeted gene expression in G. oxydans. The corrections of start codons further improve the high quality genome reference and support future proteome analysis. Electronic supplementary material The online version of this article (10.1186/s12864-017-4415-x) contains supplementary material, which is available to authorized users.
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36
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Zou X, Wu G, Stagge S, Chen L, Jönsson LJ, Hong FF. Comparison of tolerance of four bacterial nanocellulose-producing strains to lignocellulose-derived inhibitors. Microb Cell Fact 2017; 16:229. [PMID: 29268745 PMCID: PMC5738851 DOI: 10.1186/s12934-017-0846-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/13/2017] [Indexed: 01/02/2023] Open
Abstract
Background Through pretreatment and enzymatic saccharification lignocellulosic biomass has great potential as a low-cost feedstock for production of bacterial nanocellulose (BNC), a high value-added microbial product, but inhibitors formed during pretreatment remain challenging. In this study, the tolerance to lignocellulose-derived inhibitors of three new BNC-producing strains were compared to that of Komagataeibacter xylinus ATCC 23770. Inhibitors studied included furan aldehydes (furfural and 5-hydroxymethylfurfural) and phenolic compounds (coniferyl aldehyde and vanillin). The performance of the four strains in the presence and absence of the inhibitors was assessed using static cultures, and their capability to convert inhibitors by oxidation and reduction was analyzed. Results Although two of the new strains were more sensitive than ATCC 23770 to furan aldehydes, one of the new strains showed superior resistance to both furan aldehydes and phenols, and also displayed high volumetric BNC yield (up to 14.78 ± 0.43 g/L) and high BNC yield on consumed sugar (0.59 ± 0.02 g/g). The inhibitors were oxidized and/or reduced by the strains to be less toxic. The four strains exhibited strong similarities with regard to predominant bioconversion products from the inhibitors, but displayed different capacity to convert the inhibitors, which may be related to the differences in inhibitor tolerance. Conclusions This investigation provides information on different performance of four BNC-producing strains in the presence of lignocellulose-derived inhibitors. The results will be of benefit to the selection of more suitable strains for utilization of lignocellulosics in the process of BNC-production.
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Affiliation(s)
- Xiaozhou Zou
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620, China.,China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.,Group of Microbiological Engineering and Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China
| | - Guochao Wu
- China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.,Department of Chemistry, KBC Chemical-Biological Centre, Umeå University, 901 87, Umeå, Sweden
| | - Stefan Stagge
- China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.,Department of Chemistry, KBC Chemical-Biological Centre, Umeå University, 901 87, Umeå, Sweden
| | - Lin Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620, China.,China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.,Group of Microbiological Engineering and Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China
| | - Leif J Jönsson
- China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.,Department of Chemistry, KBC Chemical-Biological Centre, Umeå University, 901 87, Umeå, Sweden
| | - Feng F Hong
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620, China. .,China-Sweden Associated Research Laboratory in Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China. .,Group of Microbiological Engineering and Industrial Biotechnology, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.
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37
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Liu J, Wu S, Li Z. Recent advances in enzymatic oxidation of alcohols. Curr Opin Chem Biol 2017; 43:77-86. [PMID: 29258054 DOI: 10.1016/j.cbpa.2017.12.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/03/2017] [Accepted: 12/04/2017] [Indexed: 01/07/2023]
Abstract
Enzymatic alcohol oxidation plays an important role in chemical synthesis. In the past two years, new alcohol oxidation enzymes were developed through genome-mining and protein engineering, such as new copper radical oxidases with broad substrate scope, alcohol dehydrogenases with altered cofactor preference and a flavin-dependent alcohol oxidase with enhanced oxygen coupling. New cofactor recycling methods were reported for alcohol dehydrogenase-catalyzed oxidation with photocatalyst and coupled glutaredoxin-glutathione reductase as promising examples. Different alcohol oxidation systems were used for the oxidation of primary and secondary alcohols, especially in the cascade conversion of alcohols to lactones, lactams, chiral amines, chiral alcohols and hydroxyketones. Among them, biocatalyst with low enantioselectivity demonstrated an interesting feature for complete conversion of racemic secondary alcohols through non-enantioselective oxidation.
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Affiliation(s)
- Ji Liu
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore 117585, Singapore
| | - Shuke Wu
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore 117585, Singapore
| | - Zhi Li
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore 117585, Singapore.
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Peters B, Mientus M, Kostner D, Daniel R, Liebl W, Ehrenreich A. Expression of membrane-bound dehydrogenases from a mother of vinegar metagenome in Gluconobacter oxydans. Appl Microbiol Biotechnol 2017; 101:7901-7912. [PMID: 28916850 DOI: 10.1007/s00253-017-8479-y] [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: 04/11/2017] [Revised: 07/28/2017] [Accepted: 08/09/2017] [Indexed: 10/18/2022]
Abstract
Acetic acid bacteria are well-known for their membrane-bound dehydrogenases rapidly oxidizing a variety of substrates in the periplasm. Since many acetic acid bacteria have not been successfully cultured in the laboratory yet, studying membrane-bound dehydrogenases directly from a metagenome of vinegar microbiota seems to be a promising way to identify novel variants of these enzymes. To this end, DNA from a mother of vinegar was isolated, sequenced, and screened for membrane-bound dehydrogenases using an in silico approach. Six metagenomic dehydrogenases were successfully expressed using an expression vector with native promoters in the acetic acid bacterium strain Gluconobacter oxydans BP.9, which is devoid of its major native membrane-bound dehydrogenases. Determining the substrates converted by these enzymes, using a whole-cell DCPIP assay, revealed one glucose dehydrogenase with an enlarged substrate spectrum additionally oxidizing aldoheptoses, D-ribose and aldotetroses, one polyol dehydrogenase with an extreme diminished spectrum but distinguishing cis and trans-1,2-cyclohexandiol and a completely new secondary alcohol dehydrogenase, which oxidizes secondary alcohols with a hydroxyl group at position 2, as long as no primary hydroxyl group is present. Three further dehydrogenases were found with substrate spectra similar to known dehydrogenases of G. oxydans 621H.
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Affiliation(s)
- Björn Peters
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Straße 4, 85354, Freising, Germany
| | - Markus Mientus
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Straße 4, 85354, Freising, Germany
| | - David Kostner
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Straße 4, 85354, Freising, Germany
| | - Rolf Daniel
- Institut für Mikrobiologie und Genetik, Genomische und Angewandte Mikrobiologie, Georg-August-Universität Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Wolfgang Liebl
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Straße 4, 85354, Freising, Germany
| | - Armin Ehrenreich
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Straße 4, 85354, Freising, Germany.
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