1
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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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2
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Battling S, Pastoors J, Deitert A, Götzen T, Hartmann L, Schröder E, Yordanov S, Büchs J. Development of a novel defined minimal medium for Gluconobacter oxydans 621H by systematic investigation of metabolic demands. J Biol Eng 2022; 16:31. [DOI: 10.1186/s13036-022-00310-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/17/2022] [Indexed: 11/23/2022] Open
Abstract
Abstract
Background
Historically, complex media are used for the cultivation of Gluconobacter oxydans in industry and research. Using complex media has different drawbacks like higher costs for downstream processing and significant variations in fermentation performances. Synthetic media can overcome those drawbacks, lead to reproducible fermentation performances. However, the development of a synthetic medium is time and labour consuming. Detailed knowledge about auxotrophies and metabolic requirements of G. oxydans is necessary. In this work, we use a systematic approach applying the in-house developed μRAMOS technology to identify auxotrophies and develop a defined minimal medium for cultivation of G. oxydans fdh, improving the production process of the natural sweetener 5-ketofructose.
Results
A rich, defined synthetic medium, consisting of 48 components, including vitamins, amino acids and trace elements, was used as a basis for medium development. In a comprehensive series of experiments, component groups and single media components were individually omitted from or supplemented to the medium and analysed regarding their performance. Main components like salts and trace elements were necessary for the growth of G. oxydans fdh, whereas nucleotides were shown to be non-essential. Moreover, results indicated that the amino acids isoleucine, glutamate and glycine and the vitamins nicotinic acid, pantothenic acid and p-aminobenzoic acid are necessary for the growth of G. oxydans fdh. The glutamate concentration was increased three-fold, functioning as a precursor for amino acid synthesis. Finally, a defined minimal medium called ‘Gluconobacter minimal medium’ was developed. The performance of this medium was tested in comparison with commonly used media for Gluconobacter. Similar/competitive results regarding cultivation time, yield and productivity were obtained. Moreover, the application of the medium in a fed-batch fermentation process was successfully demonstrated.
Conclusion
The systematic investigation of a wide range of media components allowed the successful development of the Gluconobacter minimal medium. This chemically defined medium contains only 14 ingredients, customised for the cultivation of G. oxydans fdh and 5-ketofructose production. This enables a more straightforward process development regarding upstream and downstream processing. Moreover, metabolic demands of G. oxydans were identified, which further can be used in media or strain development for different processes.
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Hövels M, Gallala N, Keriakes SL, König AP, Schiessl J, Laporte T, Kosciow K, Deppenmeier U. 5-Keto-D-Fructose, a Natural Diketone and Potential Sugar Substitute, Significantly Reduces the Viability of Prokaryotic and Eukaryotic Cells. Front Microbiol 2022; 13:935062. [PMID: 35801101 PMCID: PMC9253636 DOI: 10.3389/fmicb.2022.935062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 05/30/2022] [Indexed: 11/24/2022] Open
Abstract
5-Keto-D-fructose (5-KF) is a natural diketone occurring in micromolar concentrations in honey, white wine, and vinegar. The oxidation of D-fructose to 5-KF is catalyzed by the membrane-bound fructose dehydrogenase complex found in several acetic acid bacteria. Since 5-KF has a sweetening power comparable to fructose and is presumably calorie-free, there is great interest in making the diketone commercially available as a new sugar substitute. Based on a genetically modified variant of the acetic acid bacterium Gluconobacter oxydans 621H, an efficient process for the microbial production of 5-KF was recently developed. However, data on the toxicology of the compound are completely lacking to date. Therefore, this study aimed to investigate the effect of 5-KF on the viability of prokaryotic and eukaryotic cells. It was found that the compound significantly inhibited the growth of the gram-positive and gram-negative model organisms Bacillus subtilis and Escherichia coli in a concentration-dependent manner. Furthermore, cell viability assays confirmed severe cytotoxicity of 5-KF toward the colon cancer cell line HT-29. Since these effects already occurred at concentrations of 5 mM, the use of 5-KF in the food sector should be avoided. The studies performed revealed that in the presence of amines, 5-KF promoted a strong Maillard reaction. The inherent reactivity of 5-KF as well as the Maillard products formed could be the trigger for the observed inhibition of prokaryotic and eukaryotic cells.
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Affiliation(s)
- Marcel Hövels
- Institute for Microbiology and Biotechnology, University of Bonn, Bonn, Germany
| | - Nicole Gallala
- Institute for Microbiology and Biotechnology, University of Bonn, Bonn, Germany
| | | | - Anna Paulina König
- Institute for Microbiology and Biotechnology, University of Bonn, Bonn, Germany
| | - Jacqueline Schiessl
- Institute for Microbiology and Biotechnology, University of Bonn, Bonn, Germany
| | - Tobias Laporte
- Institute for Microbiology and Biotechnology, University of Bonn, Bonn, Germany
| | - Konrad Kosciow
- German Aerospace Center (DLR), Institute for the Protection of Terrestrial Infrastructures, Sankt Augustin, Germany
| | - Uwe Deppenmeier
- Institute for Microbiology and Biotechnology, University of Bonn, Bonn, Germany
- *Correspondence: Uwe Deppenmeier,
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Qin Z, Yu S, Chen J, Zhou J. Dehydrogenases of acetic acid bacteria. Biotechnol Adv 2021; 54:107863. [PMID: 34793881 DOI: 10.1016/j.biotechadv.2021.107863] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 12/13/2022]
Abstract
Acetic acid bacteria (AAB) are a group of bacteria that can oxidize many substrates such as alcohols and sugar alcohols and play important roles in industrial biotechnology. A majority of industrial processes that involve AAB are related to their dehydrogenases, including PQQ/FAD-dependent membrane-bound dehydrogenases and NAD(P)+-dependent cytoplasmic dehydrogenases. These cofactor-dependent dehydrogenases must effectively regenerate their cofactors in order to function continuously. For PQQ, FAD and NAD(P)+ alike, regeneration is directly or indirectly related to the electron transport chain (ETC) of AAB, which plays an important role in energy generation for aerobic cell growth. Furthermore, in changeable natural habitats, ETC components of AAB can be regulated so that the bacteria survive in different environments. Herein, the progressive cascade in an application of AAB, including key dehydrogenases involved in the application, regeneration of dehydrogenase cofactors, ETC coupling with cofactor regeneration and ETC regulation, is systematically reviewed and discussed. As they have great application value, a deep understanding of the mechanisms through which AAB function will not only promote their utilization and development but also provide a reference for engineering of other industrial strains.
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Affiliation(s)
- Zhijie Qin
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shiqin Yu
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jian Chen
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
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5
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Wohlers K, Wirtz A, Reiter A, Oldiges M, Baumgart M, Bott M. Metabolic engineering of Pseudomonas putida for production of the natural sweetener 5-ketofructose from fructose or sucrose by periplasmic oxidation with a heterologous fructose dehydrogenase. Microb Biotechnol 2021; 14:2592-2604. [PMID: 34437751 PMCID: PMC8601194 DOI: 10.1111/1751-7915.13913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/13/2021] [Indexed: 11/30/2022] Open
Abstract
5-Ketofructose (5-KF) is a promising low-calorie natural sweetener with the potential to reduce health problems caused by excessive sugar consumption. It is formed by periplasmic oxidation of fructose by fructose dehydrogenase (Fdh) of Gluconobacter japonicus, a membrane-bound three-subunit enzyme containing FAD and three haemes c as prosthetic groups. This study aimed at establishing Pseudomonas putida KT2440 as a new cell factory for 5-KF production, as this host offers a number of advantages compared with the established host Gluconobacter oxydans. Genomic expression of the fdhSCL genes from G. japonicus enabled synthesis of functional Fdh in P. putida and successful oxidation of fructose to 5-KF. In a batch fermentation, 129 g l-1 5-KF were formed from 150 g l-1 fructose within 23 h, corresponding to a space-time yield of 5.6 g l-1 h-1 . Besides fructose, also sucrose could be used as substrate for 5-KF production by plasmid-based expression of the invertase gene inv1417 from G. japonicus. In a bioreactor cultivation with pulsed sucrose feeding, 144 g 5-KF were produced from 358 g sucrose within 48 h. These results demonstrate that P. putida is an attractive host for 5-KF production.
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Affiliation(s)
- Karen Wohlers
- IBG‐1: BiotechnologyInstitute of Bio‐ and GeosciencesForschungszentrum JülichJülich52425Germany
| | - Astrid Wirtz
- IBG‐1: BiotechnologyInstitute of Bio‐ and GeosciencesForschungszentrum JülichJülich52425Germany
| | - Alexander Reiter
- IBG‐1: BiotechnologyInstitute of Bio‐ and GeosciencesForschungszentrum JülichJülich52425Germany
- Institute of BiotechnologyRWTH Aachen UniversityAachen52062Germany
| | - Marco Oldiges
- IBG‐1: BiotechnologyInstitute of Bio‐ and GeosciencesForschungszentrum JülichJülich52425Germany
- Institute of BiotechnologyRWTH Aachen UniversityAachen52062Germany
| | - Meike Baumgart
- IBG‐1: BiotechnologyInstitute of Bio‐ and GeosciencesForschungszentrum JülichJülich52425Germany
| | - Michael Bott
- IBG‐1: BiotechnologyInstitute of Bio‐ and GeosciencesForschungszentrum JülichJülich52425Germany
- The Bioeconomy Science Center (BioSC)Forschungszentrum JülichJülichD‐52425Germany
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Doan CT, Tran TN, Nguyen TT, Tran TPH, Nguyen VB, Tran TD, Nguyen AD, Wang SL. Production of Sucrolytic Enzyme by Bacillus licheniformis by the Bioconversion of Pomelo Albedo as a Carbon Source. Polymers (Basel) 2021; 13:polym13121959. [PMID: 34199171 PMCID: PMC8231626 DOI: 10.3390/polym13121959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/10/2021] [Accepted: 06/10/2021] [Indexed: 11/30/2022] Open
Abstract
Recently, there has been increasing use of agro-byproducts in microbial fermentation to produce a variety of value-added products. In this study, among various kinds of agro-byproducts, pomelo albedo powder (PAP) was found to be the most effective carbon source for the production of sucrose hydrolyzing enzyme by Bacillus licheniformis TKU004. The optimal medium for sucrolytic enzyme production contained 2% PAP, 0.75% NH4NO3, 0.05% MgSO4, and 0.05% NaH2PO4 and the optimal culture conditions were pH 6.7, 35 °C, 150 rpm, and 24 h. Accordingly, the highest sucrolytic activity was 1.87 U/mL, 4.79-fold higher than that from standard conditions using sucrose as the carbon source. The purified sucrolytic enzyme (sleTKU004) is a 53 kDa monomeric protein and belongs to the glycoside hydrolase family 68. The optimum temperature and pH of sleTKU004 were 50 °C, and pH = 6, respectively. SleTKU004 could hydrolyze sucrose, raffinose, and stachyose by attacking the glycoside linkage between glucose and fructose molecules of the sucrose unit. The Km and Vmax of sleTKU004 were 1.16 M and 5.99 µmol/min, respectively. Finally, sleTKU004 showed strong sucrose tolerance and presented the highest hydrolytic activity at the sucrose concentration of 1.2 M–1.5 M.
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Affiliation(s)
- Chien Thang Doan
- Department of Chemistry, Tamkang University, New Taipei City 25137, Taiwan; (C.T.D.); (T.N.T.)
- Faculty of Natural Sciences and Technology, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (T.T.N.); (T.P.H.T.); (T.D.T.)
| | - Thi Ngoc Tran
- Department of Chemistry, Tamkang University, New Taipei City 25137, Taiwan; (C.T.D.); (T.N.T.)
- Faculty of Natural Sciences and Technology, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (T.T.N.); (T.P.H.T.); (T.D.T.)
| | - Thi Thanh Nguyen
- Faculty of Natural Sciences and Technology, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (T.T.N.); (T.P.H.T.); (T.D.T.)
| | - Thi Phuong Hanh Tran
- Faculty of Natural Sciences and Technology, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (T.T.N.); (T.P.H.T.); (T.D.T.)
| | - Van Bon Nguyen
- Institute of Biotechnology and Environment, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (V.B.N.); (A.D.N.)
| | - Trung Dung Tran
- Faculty of Natural Sciences and Technology, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (T.T.N.); (T.P.H.T.); (T.D.T.)
| | - Anh Dzung Nguyen
- Institute of Biotechnology and Environment, Tay Nguyen University, Buon Ma Thuot 630000, Vietnam; (V.B.N.); (A.D.N.)
| | - San-Lang Wang
- Department of Chemistry, Tamkang University, New Taipei City 25137, Taiwan; (C.T.D.); (T.N.T.)
- Life Science Development Center, Tamkang University, New Taipei City 25137, Taiwan
- Correspondence: ; Tel.: +886-2-2621-5656; Fax: +886-2-2620-9924
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7
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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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8
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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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9
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Degradation of the low-calorie sugar substitute 5-ketofructose by different bacteria. Appl Microbiol Biotechnol 2021; 105:2441-2453. [PMID: 33616697 PMCID: PMC7954740 DOI: 10.1007/s00253-021-11168-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/28/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022]
Abstract
Abstract There is an increasing public awareness about the danger of dietary sugars with respect to their caloric contribution to the diet and the rise of overweight throughout the world. Therefore, low-calorie sugar substitutes are of high interest to replace sugar in foods and beverages. A promising alternative to natural sugars and artificial sweeteners is the fructose derivative 5-keto-D-fructose (5-KF), which is produced by several Gluconobacter species. A prerequisite before 5-KF can be used as a sweetener is to test whether the compound is degradable by microorganisms and whether it is metabolized by the human microbiota. We identified different environmental bacteria (Tatumella morbirosei, Gluconobacter japonicus LMG 26773, Gluconobacter japonicus LMG 1281, and Clostridium pasteurianum) that were able to grow with 5-KF as a substrate. Furthermore, Gluconobacter oxydans 621H could use 5-KF as a carbon and energy source in the stationary growth phase. The enzymes involved in the utilization of 5-KF were heterologously overproduced in Escherichia coli, purified and characterized. The enzymes were referred to as 5-KF reductases and belong to three unrelated enzymatic classes with highly different amino acid sequences, activities, and structural properties. Furthermore, we could show that 15 members of the most common and abundant intestinal bacteria cannot degrade 5-KF, indicating that this sugar derivative is not a suitable growth substrate for prokaryotes in the human intestine. Key points • Some environmental bacteria are able to use 5-KF as an energy and carbon source. • Four 5-KF reductases were identified, belonging to three different protein families. • Many gut bacteria cannot degrade 5-KF. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-021-11168-3.
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Adachi O, Nguyen TM, Hours RA, Kataoka N, Matsushita K, Akakabe Y, Yakushi T. 5-Keto-D-fructose production from sugar alcohol by isolated wild strain Gluconobacter frateurii CHM 43. Biosci Biotechnol Biochem 2020; 84:1745-1747. [DOI: 10.1080/09168451.2020.1767500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
Gluconobacter frateurii
CHM 43 have D-mannitol dehydrogenase (quinoprotein glycerol dehydrogenase) and flavoprotein D-fructose dehydrogenase in the membranes. When the two enzymes are functional, D-mannitol is converted to 5-keto-D-fructose with 65% yield when cultivated on D-mannitol. 5-Keto-D-fructose production with almost 100% yield was realized with the resting cells. The method proposed here should give a smart strategy for 5-keto-D-fructose production.
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Affiliation(s)
- Osao Adachi
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan
| | - Thuy M Nguyen
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan
| | - Roque A Hours
- CINDEFI, School of Science, La Plata National University, La Plata, Argentina
| | - Naoya Kataoka
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan
| | - Kazunobu Matsushita
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan
| | - Yoshihiko Akakabe
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan
| | - Toshiharu Yakushi
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan
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11
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Battling S, Wohlers K, Igwe C, Kranz A, Pesch M, Wirtz A, Baumgart M, Büchs J, Bott M. Novel plasmid-free Gluconobacter oxydans strains for production of the natural sweetener 5-ketofructose. Microb Cell Fact 2020; 19:54. [PMID: 32131833 PMCID: PMC7055074 DOI: 10.1186/s12934-020-01310-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/17/2020] [Indexed: 12/14/2022] Open
Abstract
Background 5-Ketofructose (5-KF) has recently been identified as a promising non-nutritive natural sweetener. Gluconobacter oxydans strains have been developed that allow efficient production of 5-KF from fructose by plasmid-based expression of the fructose dehydrogenase genes fdhSCL of Gluconobacter japonicus. As plasmid-free strains are preferred for industrial production of food additives, we aimed at the construction of efficient 5-KF production strains with the fdhSCL genes chromosomally integrated. Results For plasmid-free 5-KF production, we selected four sites in the genome of G. oxydans IK003.1 and inserted the fdhSCL genes under control of the strong P264 promoter into each of these sites. All four recombinant strains expressed fdhSCL and oxidized fructose to 5-KF, but site-specific differences were observed suggesting that the genomic vicinity influenced gene expression. For further improvement, a second copy of the fdhSCL genes under control of P264 was inserted into the second-best insertion site to obtain strain IK003.1::fdhSCL2. The 5-KF production rate and the 5-KF yield obtained with this double-integration strain were considerably higher than for the single integration strains and approached the values of IK003.1 with plasmid-based fdhSCL expression. Conclusion We identified four sites in the genome of G. oxydans suitable for expression of heterologous genes and constructed a strain with two genomic copies of the fdhSCL genes enabling efficient plasmid-free 5-KF production. This strain will serve as basis for further metabolic engineering strategies aiming at the use of alternative carbon sources for 5-KF production and for bioprocess optimization.
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Affiliation(s)
- Svenja Battling
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Karen Wohlers
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Chika Igwe
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Angela Kranz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Matthias Pesch
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Astrid Wirtz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Jochen Büchs
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany.
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany.
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