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Shaimerdenova U, Kaiyrmanova G, Lewandowska W, Bartoszewicz M, Swiecicka I, Yernazarova A. Biosurfactant and biopolymer producing microorganisms from West Kazakhstan oilfield. Sci Rep 2024; 14:2294. [PMID: 38280982 PMCID: PMC10821952 DOI: 10.1038/s41598-024-52906-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 01/24/2024] [Indexed: 01/29/2024] Open
Abstract
Microbiological enhanced oil recovery (MEOR) uses indigenous or exogenous microorganisms and nutrients to enhance oil production through synthesis of metabolites reducing oil viscosity and surface tension. In order to find bacteria suitable for MEOR, we studied 26 isolates from wells in the Akingen oilfield in West Kazakhstan. Six of them were selected for further analysis based on their ability to reduce surface tension to less than 40 mN/m, with the A9 isolate exhibiting tension reduction values of 32.76 ± 0.3 mN/m. Based on the morphological features, biochemical activities, and the 16S rRNA gene, the isolates were classified to the Bacillus subtilis group. In the phylogenetic analysis the isolates grouped into two main clusters. Genes encoding the surfactin synthetase subunits were found in A2, A8, A9, A12, PW2, only the PW2 strain had lchAA encoding lichenysin, while sacB encoding levan was noted in A2, A8, A9, and A12. The expression of srfAB, srfAC, and sacB tested with qPCR varied among strains. Nevertheless, whereas temperature moderately affects the expression level, with the highest level recorded at 40 °C, salinity significantly impacts the expression of the genes encoding biosurfactants. B. subtilis strains isolated in the study, especially A9, are promising for microbial-enhanced oil recovery.
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Affiliation(s)
- Ulzhan Shaimerdenova
- Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, 71 Al-Farabi Ave, 050038, Almaty, Kazakhstan
| | - Gulzhan Kaiyrmanova
- Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, 71 Al-Farabi Ave, 050038, Almaty, Kazakhstan
| | - Wioleta Lewandowska
- Doctoral School of Exact and Natural Sciences, University of Białystok, 1K Konstanty Ciołkowski Str, 15-245, Białystok, Poland
| | - Marek Bartoszewicz
- Faculty of Biology, University of Bialystok, 1J Konstanty Ciołkowski Str, 15-245, Bialystok, Poland
| | - Izabela Swiecicka
- Faculty of Biology, University of Bialystok, 1J Konstanty Ciołkowski Str, 15-245, Bialystok, Poland
- Laboratory of Applied Microbiology, Faculty of Biology, University of Bialystok, 1J Konstanty Ciołkowski Str, 15-245, Bialystok, Poland
| | - Aliya Yernazarova
- Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, 71 Al-Farabi Ave, 050038, Almaty, Kazakhstan.
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Tsigoriyna L, Arsov A, Gergov E, Petrova P, Petrov K. Influence of pH on Inulin Conversion to 2,3-Butanediol by Bacillus licheniformis 24: A Gene Expression Assay. Int J Mol Sci 2023; 24:14065. [PMID: 37762368 PMCID: PMC10531509 DOI: 10.3390/ijms241814065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
2,3-Butanediol (2,3-BD) is an alcohol highly demanded in the chemical, pharmaceutical, and food industries. Its microbial production, safe non-pathogenic producer strains, and suitable substrates have been avidly sought in recent years. The present study investigated 2,3-BD synthesis by the GRAS Bacillus licheniformis 24 using chicory inulin as a cheap and renewable substrate. The process appears to be pH-dependent. At pH 5.25, the synthesis of 2,3-BD was barely detectable due to the lack of inulin hydrolysis. At pH 6.25, 2,3-BD concentration reached 67.5 g/L with rapid hydrolysis of the substrate but was accompanied by exopolysaccharide (EPS) synthesis. Since inulin conversion by bacteria is a complex process and begins with its hydrolysis, the question of the acting enzymes arose. Genome mining revealed that several glycoside hydrolase (GH) enzymes from different CAZy families are involved. Five genes encoding such enzymes in B. licheniformis 24 were amplified and sequenced: sacA, sacB, sacC, levB, and fruA. Real-time RT-PCR experiments showed that the process of inulin hydrolysis is regulated at the level of gene expression, as four genes were significantly overexpressed at pH 6.25. In contrast, the expression of levB remained at the same level at the different pH values at all-time points. It was concluded that the sacC and sacA/fruA genes are crucial for inulin hydrolysis. They encode exoinulinase (EC 3.2.1.80) and sucrases (EC 3.2.1.26), respectively. The striking overexpression of sacB under these conditions led to increased synthesis of EPS; therefore, the simultaneous production of 2,3-BD and EPS cannot be avoided.
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Affiliation(s)
- Lidia Tsigoriyna
- Institute of Chemical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Alexander Arsov
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (P.P.)
| | - Emanoel Gergov
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (P.P.)
| | - Penka Petrova
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (P.P.)
| | - Kaloyan Petrov
- Institute of Chemical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Domżał-Kędzia M, Ostrowska M, Lewińska A, Łukaszewicz M. Recent Developments and Applications of Microbial Levan, A Versatile Polysaccharide-Based Biopolymer. Molecules 2023; 28:5407. [PMID: 37513279 PMCID: PMC10384002 DOI: 10.3390/molecules28145407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/09/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Polysaccharides are essential components with diverse functions in living organisms and find widespread applications in various industries. They serve as food additives, stabilizers, thickeners, and fat substitutes in the food industry, while also contributing to dietary fiber for improved digestion and gut health. Plant-based polysaccharides are utilized in paper, textiles, wound dressings, biodegradable packaging, and tissue regeneration. Polysaccharides play a crucial role in medicine, pharmacy, and cosmetology, as well as in the production of biofuels and biomaterials. Among microbial biopolymers, microbial levan, a fructose polysaccharide, holds significant promise due to its high productivity and chemical diversity. Levan exhibits a wide range of properties, including film-forming ability, biodegradability, non-toxicity, self-aggregation, encapsulation, controlled release capacity, water retention, immunomodulatory and prebiotic activity, antimicrobial and anticancer activity, as well as high biocompatibility. These exceptional properties position levan as an attractive candidate for nature-based materials in food production, modern cosmetology, medicine, and pharmacy. Advancing the understanding of microbial polymers and reducing production costs is crucial to the future development of these fields. By further exploring the potential of microbial biopolymers, particularly levan, we can unlock new opportunities for sustainable materials and innovative applications that benefit various industries and contribute to advancements in healthcare, environmental conservation, and biotechnology.
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Affiliation(s)
- Marta Domżał-Kędzia
- Faculty of Biotechnology, University of Wroclaw, Joliot Curie 14a, 50-383 Wroclaw, Poland
- Research and Development Department InventionBio S.A., Jakóba Hechlińskiego 4, 85-825 Bydgoszcz, Poland
| | - Monika Ostrowska
- Research and Development Department InventionBio S.A., Jakóba Hechlińskiego 4, 85-825 Bydgoszcz, Poland
| | - Agnieszka Lewińska
- Faculty of Chemistry, University of Wroclaw, Joliot Curie 14, 50-383 Wroclaw, Poland
- OnlyBio Life S.A., Jakóba Hechlińskiego 6, 85-825 Bydgoszcz, Poland
| | - Marcin Łukaszewicz
- Faculty of Biotechnology, University of Wroclaw, Joliot Curie 14a, 50-383 Wroclaw, Poland
- Research and Development Department InventionBio S.A., Jakóba Hechlińskiego 4, 85-825 Bydgoszcz, Poland
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Lekakarn H, Bunterngsook B, Jaikaew P, Kuantum T, Wansuksri R, Champreda V. Functional Characterization of Recombinant Endo-Levanase (LevBk) from Bacillus koreensis HL12 on Short-Chain Levan-Type Fructooligosaccharides Production. Protein J 2022; 41:477-488. [PMID: 35931938 DOI: 10.1007/s10930-022-10069-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2022] [Indexed: 10/15/2022]
Abstract
Levan-type fructooligosaccharides (L-FOSs) are a prominent class of non-digestible oligosaccharides with potential as nutritional prebiotics. Endo-levanase, which randomly hydrolyzes β-(2,6)-linkages in fructans, is a promising enzyme for short-chain FOS production. In this work, a recombinant levanase (LevBk) from Bacillus koreensis strain HL12 was characterized. Soluble LevBk protein was produced in Escherichia coli BL21(DE3) system at 40 mg/L of culture medium. Based on sequence and structural analysis, LevBk was classified as a member of endo-levanase in GH32 family containing N-terminal substrate binding pocket and C-terminal β-sandwich domains. LevBk optimally worked at 45 °C, pH 6.0 with the specific activity of 2.43 U/mg. Based on enzymatic hydrolysis, short-chain L-FOSs with degree of polymerization (DP) of 2-4 were produced from hydrolysis of timothy grass levan under optimal conditions for 9-24 h. With its ability to produce L-FOSs with specific chain lengths, LevBk could be attractively applied for converting of levan containing material to high value-added sweetener in the biorefinery industry.
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Affiliation(s)
- Hataikarn Lekakarn
- Department of Biotechnology, Faculty of Science and Technology, Rangsit Campus, Thammasat University, Pathum Thani, 12120, Thailand
| | - Benjarat Bunterngsook
- Enzyme Technology Research Team, Biorefinery Technology and Bioproduct Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120, Thailand.
| | - Phuphiphat Jaikaew
- Department of Biotechnology, Faculty of Science and Technology, Rangsit Campus, Thammasat University, Pathum Thani, 12120, Thailand
| | - Thanyanun Kuantum
- Department of Biotechnology, Faculty of Science and Technology, Rangsit Campus, Thammasat University, Pathum Thani, 12120, Thailand
| | - Rungtiva Wansuksri
- Cassava and Starch Technology Research Team, Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, Bangkok, 10900, Thailand
| | - Verawat Champreda
- Enzyme Technology Research Team, Biorefinery Technology and Bioproduct Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120, Thailand
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Levan-type fructooligosaccharides synthesis by novel levansucrase-inulosucrase fusion enzyme. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Bacillus subtilis PS-216 Antagonistic Activities against Campylobacter jejuni NCTC 11168 Are Modulated by Temperature, Oxygen, and Growth Medium. Microorganisms 2022; 10:microorganisms10020289. [PMID: 35208741 PMCID: PMC8875091 DOI: 10.3390/microorganisms10020289] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 02/01/2023] Open
Abstract
As the incidence of Campylobacter jejuni and campylobacteriosis grows, so does the need for a better understanding and control of this pathogen. We studied the interactions of C. jejuni NCTC 11168 and a potential probiotic, Bacillus subtilis PS-216, in cocultures at different starting ratios and temperatures (20 °C, 37 °C, 42 °C), under different atmospheres (aerobic, microaerobic), and in different growth media (Mueller–Hinton, chicken litter medium, chicken intestinal-content medium). Under microaerobic conditions, B. subtilis effectively inhibited the growth of C. jejuni at 42 °C (log reduction, 4.19), even when C. jejuni counts surpassed B. subtilis by 1000-fold in the starting inoculum. This inhibition was weaker at 37 °C (log reduction, 1.63), while no impact on CFUs was noted at 20 °C, which is a temperature nonpermissive of C. jejuni growth. Under aerobic conditions, B. subtilis supported C. jejuni survival. B. subtilis PS-216 inhibited the growth of C. jejuni in sterile chicken litter (4.07 log reduction) and in sterile intestinal content (2.26 log reduction). In nonsterile intestinal content, B. subtilis PS-216 was able to grow, to a lesser extent, compared to Mueller–Hinton media, still showing potential as a chicken probiotic that could be integrated into the chicken intestinal microbiota. This study showed the strong influence of environmental parameters on the variability of C. jejuni and B. subtilis interactions. Furthermore, B. subtilis PS-216 antagonism was strongest against C. jejuni NCTC 11168 under conditions that might represent conditions in the chicken environment (42 °C, microaerobic atmosphere, chicken litter medium).
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Wangpaiboon K, Klaewkla M, Charoenwongpaiboon T, Vongkusolkit N, Panpetch P, Kuttiyawong K, Visessanguan W, Pichyangkura R. Synergistic enzyme cocktail between levansucrase and inulosucrase for superb levan-type fructooligosaccharide synthesis. Enzyme Microb Technol 2021; 154:109960. [PMID: 34923315 DOI: 10.1016/j.enzmictec.2021.109960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/17/2021] [Accepted: 12/04/2021] [Indexed: 11/24/2022]
Abstract
Inulosucrase (ISC) and levansucrase (LSC) utilise sucrose and produce inulin- and levan-type fructans, respectively. This study aims to propose a new strategy to improve levan-type fructooligosaccharide (L-FOS) production. The effect of ISC/ LSC -mixed reaction was elucidated on L-FOS production. The presence of ISC in the LSC reaction significantly leads to the higher production of L-FOSs as the main products. Furthermore, the different ratios between ISC and LSC affected the distribution of L-FOSs. A greater amount of ISC compared to LSC promoted the synthesis of short-chain L-FOSs. Conversely, when LSC was increased, the synthesis of longer-chain L-FOSs was enhanced. The addition of trisaccharide mixtures obtained from either a single ISC or LSC reaction could enhance L-FOSs synthesis in the LSC reaction. Analysis of these trisaccharides revealed that most species of the oligosaccharides were similar, with 1-kestose being the major one. The supplement of only 1-kestose in the LSC reaction showed similar results to those of the reaction in the presence of trisaccharide mixtures. Moreover, the results were supported by molecular dynamics simulations. This work not only provides an improvement in L-FOS production but also revealed and supported some insights into the mechanism of fructansucrases.
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Affiliation(s)
- Karan Wangpaiboon
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Methus Klaewkla
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | | | - Napas Vongkusolkit
- Department of Biology, Barnard College, Columbia University, New York, NY 10027, USA
| | - Pawinee Panpetch
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kamontip Kuttiyawong
- Department of Chemistry, Faculty of Liberal Arts and Science, Kasetsart University Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
| | - Wonnop Visessanguan
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholayothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Rath Pichyangkura
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
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Zhang X, Liang Y, Yang H, Yang H, Chen S, Huang F, Hou Y, Huang R. A novel fusion levansucrase improves thermostability of polymerization and production of high molecular weight levan. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Wang Y, Mittermaier AK. Characterizing Bi-substrate Enzyme Kinetics at High Resolution by 2D-ITC. Anal Chem 2021; 93:12723-12732. [PMID: 34514786 DOI: 10.1021/acs.analchem.1c02705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
There is growing interest in using isothermal titration calorimetry (ITC) to characterize enzyme kinetics by measuring the heat produced or absorbed by catalysis in real time. Since virtually all chemical reactions are associated with changes in enthalpy, ITC represents a robust and nearly universal experimental approach. Nevertheless, there are technical challenges that limit ITC's applicability. For instance, the full kinetic characterization of enzymes with two substrates (bi-substrate enzymes), which comprise the majority of known examples, requires a series of experiments to be performed as the concentrations of both substrates are varied. This is a time-consuming and expensive process using current ITC methods since many (>5) individual experiments must be performed independently to obtain a sufficient quantity of data. We have developed a new ITC method, which we term 2D-ITC, which maps the reaction velocity as a function of two substrate concentrations in a single, roughly 2 h long experiment. This method provides a level of detail that rivals or exceeds any existing enzyme assay, as a single experiment generates on the order of 7000 catalytic rate measurements. In a proof-of-principle application to rabbit muscle pyruvate kinase (rMPK), the method correctly identified the enzyme's random sequential mechanism and allosteric catalytic suppression by the amino acid phenylalanine (Phe). Unexpectedly, we found that while Phe reduces affinity for the substrate phosphoenolpyruvate, a known phenomenon, it also alleviates inhibition by the reaction product ATP, which had not been reported previously. Given the relative abundance of ATP in the cell, this opposing effect is expected to have a substantial impact on rMPK activity.
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Affiliation(s)
- Yun Wang
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - Anthony K Mittermaier
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
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Kırtel O, Aydın H, Toksoy Öner E. Fructanogenic traits in halotolerant Bacillus licheniformis OK12 and their predicted functional significance. J Appl Microbiol 2021; 131:1391-1404. [PMID: 33484024 DOI: 10.1111/jam.15015] [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: 10/21/2020] [Revised: 01/08/2021] [Accepted: 01/19/2021] [Indexed: 01/26/2023]
Abstract
AIMS Isolating a novel bacterial source of fructan from a saltern and analysis of its genome to better understand the possible roles of fructans in hypersaline environments. METHODS AND RESULTS Bacteria were isolated from crude salt samples originating from Çamaltı Saltern in Western Turkey and screened for fructanogenic traits in high-salt and sucrose-rich selective medium. Exopolysaccharide accumulated in the presence of sucrose by isolate OK12 was purified and chemically characterized via HPLC, FT-IR and NMR, which revealed that it was a levan-type fructan (β-2,6 linked homopolymer of fructose). The isolate was taxonomically classified as Bacillus licheniformis OK12 through 16S rRNA gene and whole-genome sequencing methods. Strain OK12 harbours one levansucrase and two different levanase genes, which altogether were predicted to significantly contribute to intracellular glucose and fructose pools. The isolate could withstand 15% NaCl, and thus classified as a halotolerant. CONCLUSIONS Fructanogenic traits in halotolerant B. licheniformis OK12 are significant due to predicted influx of glucose and fructose as a result of levan biosynthesis and levan hydrolysis, respectively. SIGNIFICANCE AND IMPACT OF THE STUDY Fructans from the residents of hypersaline habitats are underexplored compounds and are expected to demonstrate physicochemical properties different from their non-halophilic counterparts. Revealing fructanogenic traits in the genome of a halotolerant bacterium brings up a new perspective in physiological roles of fructans.
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Affiliation(s)
- O Kırtel
- Industrial Biotechnology and Systems Biology Research Group-IBSB, Bioengineering Department, Göztepe Campus, Marmara University, Istanbul, Turkey
| | - H Aydın
- Industrial Biotechnology and Systems Biology Research Group-IBSB, Bioengineering Department, Göztepe Campus, Marmara University, Istanbul, Turkey
| | - E Toksoy Öner
- Industrial Biotechnology and Systems Biology Research Group-IBSB, Bioengineering Department, Göztepe Campus, Marmara University, Istanbul, Turkey
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Han J, Feng H, Wang X, Liu Z, Wu Z. Levan from Leuconostoc citreum BD1707: production optimization and changes in molecular weight distribution during cultivation. BMC Biotechnol 2021; 21:14. [PMID: 33541325 PMCID: PMC7863327 DOI: 10.1186/s12896-021-00673-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/26/2021] [Indexed: 11/17/2022] Open
Abstract
Background Levan is a well-known homopolymer of fructose composed predominantly of β-(2, 6) fructofuranosyl linkages in the backbone with occasional β-(2, 1) linkages in the branch chains with varied applications. However, high production cost due to low yield of microbial levan has become a bottleneck for its practical applications. Furthermore, factors affecting the molecular mass of the synthesized levan by Leuconostoc spp. during prolonged cultivation is not fully elucidated. Methods The cultivation condition for Leuconostoc citreum BD1707 to synthesize levan was optimized by single-factor experiments and subsequently with response surface methodology (RSM). The average molecular weight (Mw) of levan synthesized by the strain L.citreum BD1707 under the optimized cultivation conditions was monitored by high-performance size exclusion chromatography (HPSEC). Finally, the enzyme with levan-degrading activity was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Results The levan yield of BD1707 reached 34.86 g/L with a corresponding productivity of 7.47 g/L/d under the optimal cultivation conditions deduced by RSM, i.e., cultivation at 26 °C and 200 rpm for 112 h in tomato juice supplemented with 172 g/L sucrose with an initial pH value of 6.12. The Mw of levan reached a peak value of 2.320 × 107 Da at 6 h of cultivation under the optimized cultivation conditions and then gradually decreased to 8.809 × 106 Da after 120 h of cultivation. Conclusion The levan yield of the strain L.citreum BD1707 could be sufficiently enhanced via cultivation condition optimization. The decrease in molecular mass of the synthesized levan was attributed predominantly to the hydrolytic activity of levansucrase secreted by L.citreum BD1707 during cultivation, with an estimated Mw of 130 KD by SDS-PAGE, while the effect of acid hydrolysis could be nearly neglected. Supplementary Information The online version contains supplementary material available at 10.1186/s12896-021-00673-y.
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Affiliation(s)
- Jin Han
- State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Center of Dairy Biotechnology, Research Institute of Bright Dairy & Food Co., Ltd., Shanghai, 200436, China
| | - Huafeng Feng
- State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Center of Dairy Biotechnology, Research Institute of Bright Dairy & Food Co., Ltd., Shanghai, 200436, China
| | - Xiaohua Wang
- State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Center of Dairy Biotechnology, Research Institute of Bright Dairy & Food Co., Ltd., Shanghai, 200436, China
| | - Zhenmin Liu
- State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Center of Dairy Biotechnology, Research Institute of Bright Dairy & Food Co., Ltd., Shanghai, 200436, China
| | - Zhengjun Wu
- State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Center of Dairy Biotechnology, Research Institute of Bright Dairy & Food Co., Ltd., Shanghai, 200436, China.
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12
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Raga-Carbajal E, Díaz-Vilchis A, Rojas-Trejo SP, Rudiño-Piñera E, Olvera C. The molecular basis of the nonprocessive elongation mechanism in levansucrases. J Biol Chem 2020; 296:100178. [PMID: 33303628 PMCID: PMC7948499 DOI: 10.1074/jbc.ra120.015853] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/24/2022] Open
Abstract
Levansucrases (LSs) synthesize levan, a β2-6-linked fructose polymer, by successively transferring the fructosyl moiety from sucrose to a growing acceptor molecule. Elucidation of the levan polymerization mechanism is important for using LSs in the production of size-defined products for application in the food and pharmaceutical industries. For a deeper understanding of the levan synthesis reaction, we determined the crystallographic structure of Bacillus subtilis LS (SacB) in complex with a levan-type fructooligosaccharide and utilized site-directed mutagenesis to identify residues involved in substrate binding. The presence of a levanhexaose molecule in the central catalytic cavity allowed us to identify five substrate-binding subsites (−1, +1, +2, +3, and +4). Mutants affecting residues belonging to the identified acceptor subsites showed similar substrate affinity (Km) values to the wildtype (WT) Km value but had a lower turnover number and transfructosylation/hydrolysis ratio. Of importance, compared with the WT, the variants progressively yielded smaller-sized low-molecular-weight levans, as the affected subsites that were closer to the catalytic site, but without affecting their ability to synthesized high-molecular-weight levans. Furthermore, an additional oligosaccharide-binding site 20 Å away from the catalytic pocket was identified, and its potential participation in the elongation mechanism is discussed. Our results clarify, for the first time, the interaction of the enzyme with an acceptor/product oligosaccharide and elucidate the molecular basis of the nonprocessive levan elongation mechanism of LSs.
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Affiliation(s)
- Enrique Raga-Carbajal
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Adelaida Díaz-Vilchis
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Sonia P Rojas-Trejo
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Enrique Rudiño-Piñera
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Clarita Olvera
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
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13
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Investigating the Product Profiles and Structural Relationships of New Levansucrases with Conventional and Non-Conventional Substrates. Int J Mol Sci 2020; 21:ijms21155402. [PMID: 32751348 PMCID: PMC7432509 DOI: 10.3390/ijms21155402] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/18/2020] [Accepted: 07/24/2020] [Indexed: 12/25/2022] Open
Abstract
The synthesis of complex oligosaccharides is desired for their potential as prebiotics, and their role in the pharmaceutical and food industry. Levansucrase (LS, EC 2.4.1.10), a fructosyl-transferase, can catalyze the synthesis of these compounds. LS acquires a fructosyl residue from a donor molecule and performs a non-Lenoir transfer to an acceptor molecule, via β-(2→6)-glycosidic linkages. Genome mining was used to uncover new LS enzymes with increased transfructosylating activity and wider acceptor promiscuity, with an initial screening revealing five LS enzymes. The product profiles and activities of these enzymes were examined after their incubation with sucrose. Alternate acceptor molecules were also incubated with the enzymes to study their consumption. LSs from Gluconobacter oxydans and Novosphingobium aromaticivorans synthesized fructooligosaccharides (FOSs) with up to 13 units in length. Alignment of their amino acid sequences and substrate docking with homology models identified structural elements causing differences in their product spectra. Raffinose, over sucrose, was the preferred donor molecule for the LS from Vibrio natriegens, N. aromaticivorans, and Paraburkolderia graminis. The LSs examined were found to have wide acceptor promiscuity, utilizing monosaccharides, disaccharides, and two alcohols to a high degree.
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Jakob F, Gebrande C, Bichler RM, Vogel RF. Insights into the pH-dependent, extracellular sucrose utilization and concomitant levan formation by Gluconobacter albidus TMW 2.1191. Antonie Van Leeuwenhoek 2020; 113:863-873. [PMID: 32130597 PMCID: PMC7272483 DOI: 10.1007/s10482-020-01397-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/20/2020] [Indexed: 01/21/2023]
Abstract
Many bacteria and archaea produce the polydisperse fructose polymer levan from sucrose upon biofilm formation via extracellular levansucrases (EC 2.4.1.10). We have investigated levansucrase-release and -activities as well as molecular size of the levan formed by the acetic acid bacterium Gluconobacter albidus TMW 2.1191 at varying environmental pH conditions to obtain insight in the ecological role of its constitutively expressed levansucrase and the produced levan. A buffer system was established enabling the recovery of levansucrase-containing supernatants from preincubated cell suspensions at pH 4.3-pH 5.7. The enzyme solutions were used to produce levans at different pH values and sucrose concentrations. Finally, the amounts and size distributions of the produced levans as well as the corresponding levansucrase activities were determined and correlated with each other. The data revealed that the levansucrase was released into the environment independently of its substrate sucrose, and that more levansucrase was released at pH ≥ 5.0. The glucose release and formation of high molecular weight levans (> 3.5 kDa) from 0.1 M initial sucrose was comparable between pH ~ 4.3-5.7 using equal amounts of released levansucrase. Hence, this type of levansucrase appears to be structurally adapted to changes in the extracellular pH and to exhibit a similar total activity over a wide acidic pH range, while it produced higher amounts of larger levan molecules at higher production pH and sucrose concentrations. These findings indicate the physiological adaptation of G. albidus TMW 2.1191 to efficient colonisation of sucrose-rich habitats via released levansucrases despite changing extracellular pH conditions in course of acid formation.
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Affiliation(s)
- Frank Jakob
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Gregor-Mendel-Straße 4, 85354, Freising, Germany.
| | - Clara Gebrande
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Gregor-Mendel-Straße 4, 85354, Freising, Germany
| | - Regina M Bichler
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Gregor-Mendel-Straße 4, 85354, Freising, Germany
| | - Rudi F Vogel
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Gregor-Mendel-Straße 4, 85354, Freising, Germany
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Hundschell CS, Braun A, Wefers D, Vogel RF, Jakob F. Size-Dependent Variability in Flow and Viscoelastic Behavior of Levan Produced by Gluconobacter albidus TMW 2.1191. Foods 2020; 9:E192. [PMID: 32075024 PMCID: PMC7073539 DOI: 10.3390/foods9020192] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 12/15/2022] Open
Abstract
Levan is a fructan-type exopolysaccharide which is produced by many microbes from sucrose via extracellular levansucrases. The hydrocolloid properties of levan depend on its molecular weight, while it is unknown why and to what extent levan is functionally diverse depending on its size. The aim of our study was to gain deeper insight into the size-dependent functional variability of levan. For this purpose, levans of different sizes were produced using the water kefir isolate Gluconobacter albidus TMW 2.1191 and subsequently rheologically characterized. Three levan types could be identified, which are similarly branched, but differ significantly in their molecular size and rheological properties. The smallest levan (<107 Da), produced without adjustment of the pH, exhibited Newton-like flow behavior up to a specific concentration of 25% (w/v). By contrast, larger levans (>108 Da) produced at pH ≥ 4.5 were shear-thinning, and the levan produced at pH 5.0 showed a gel-like behavior at 5% (w/v). A third (intermediate) levan variant was obtained through production in buffers at pH 4.0 and exhibited the properties of a viscoelastic fluid up to concentrations of 15% (w/v). Our study reveals that the rheological properties of levan are determined by its size and polydispersity, rather than by the amount of levan used or the structural composition.
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Affiliation(s)
- Christoph S. Hundschell
- Chair of Technical Microbiology, Technical University of Munich, Gregor-Mendel-Straße 4, 85354 Freising, Germany;
- Department of Food Technology and Food Material Science, Technical University of Berlin, 14195 Berlin, Germany;
| | - Andre Braun
- Anton Paar Germany GmbH, Hellmuth-Hirth-Strasse 6, 73760 Ostfildern-Scharnhausen, Germany;
- Lehrstuhl für Systemverfahrenstechnik, Technische Universität München, Gregor-Mendel-Straße 4, 85354 Freising, Germany
| | - Daniel Wefers
- Division of Food Chemistry, Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle (Saale), Germany;
- Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Rudi F. Vogel
- Chair of Technical Microbiology, Technical University of Munich, Gregor-Mendel-Straße 4, 85354 Freising, Germany;
| | - Frank Jakob
- Chair of Technical Microbiology, Technical University of Munich, Gregor-Mendel-Straße 4, 85354 Freising, Germany;
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Valorization of cheese whey using microbial fermentations. Appl Microbiol Biotechnol 2020; 104:2749-2764. [DOI: 10.1007/s00253-020-10408-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/19/2020] [Accepted: 01/23/2020] [Indexed: 02/07/2023]
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A close look at the structural features and reaction conditions that modulate the synthesis of low and high molecular weight fructans by levansucrases. Carbohydr Polym 2019; 219:130-142. [DOI: 10.1016/j.carbpol.2019.05.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/13/2019] [Accepted: 05/05/2019] [Indexed: 12/13/2022]
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Understanding the transfer reaction network behind the non-processive synthesis of low molecular weight levan catalyzed by Bacillus subtilis levansucrase. Sci Rep 2018; 8:15035. [PMID: 30301900 PMCID: PMC6177408 DOI: 10.1038/s41598-018-32872-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 09/13/2018] [Indexed: 11/18/2022] Open
Abstract
Under specific reaction conditions, levansucrase from Bacillus subtilis (SacB) catalyzes the synthesis of a low molecular weight levan through the non-processive elongation of a great number of intermediates. To deepen understanding of the polymer elongation mechanism, we conducted a meticulous examination of the fructooligosaccharide profile evolution during the levan synthesis. As a result, the formation of primary and secondary intermediates series in different reaction stages was observed. The origin of the series was identified through comparison with product profiles obtained in acceptor reactions employing levanbiose, blastose, 1-kestose, 6-kestose, and neo-kestose, and supported with the isolation and NMR analyses of some relevant products, demonstrating that all of them are inherent products during levan formation from sucrose. These results allowed to establish the network of fructosyl transfer reactions involved in the non-processive levan synthesis. Overall, our results reveal how the relaxed acceptor specificity of SacB during the initial steps of the synthesis is responsible for the formation of several levan series, which constitute the final low molecular weight levan distribution.
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Kırtel O, Versluys M, Van den Ende W, Toksoy Öner E. Fructans of the saline world. Biotechnol Adv 2018; 36:1524-1539. [DOI: 10.1016/j.biotechadv.2018.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 06/08/2018] [Accepted: 06/14/2018] [Indexed: 10/28/2022]
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Kirtel O, Menéndez C, Versluys M, Van den Ende W, Hernández L, Toksoy Öner E. Levansucrase from Halomonas smyrnensis AAD6T: first halophilic GH-J clan enzyme recombinantly expressed, purified, and characterized. Appl Microbiol Biotechnol 2018; 102:9207-9220. [DOI: 10.1007/s00253-018-9311-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/03/2018] [Accepted: 08/06/2018] [Indexed: 12/21/2022]
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21
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La China S, Zanichelli G, De Vero L, Gullo M. Oxidative fermentations and exopolysaccharides production by acetic acid bacteria: a mini review. Biotechnol Lett 2018; 40:1289-1302. [DOI: 10.1007/s10529-018-2591-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/03/2018] [Indexed: 02/07/2023]
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Lee SY, Shin WR, Sekhon SS, Lee JP, Kim YC, Ahn JY, Kim YH. Molecular Docking Analysis and Biochemical Evaluation of Levansucrase from Sphingobium chungbukense DJ77. ACS COMBINATORIAL SCIENCE 2018; 20:414-422. [PMID: 29812898 DOI: 10.1021/acscombsci.8b00002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bacterial exopolymer Levan (β-(2,6) polyfructan) synthesized by levansucrase has attracted interest for various applications due to its low intrinsic viscosity compared with other polysaccharides. We report a novel levansucrase (Lsc) isolated from Sphingobium chunbukense DJ77 and verify its biochemical characteristics by comparative analysis of molecular docking analysis (MOE) and catalytic residue analysis. The complete sequence of the Lsc encoding gene ( lsc) was cloned under the direction of the T7 promoter and purified in an Escherichia coli BL21 (DE3) protein expression system. The enzyme activity analysis and ligand docking MOE study of S. chungbukense DJ77 Lsc revealed that Arg 77, Ser112, Arg 195, Asp196, Glu257, and Gln275 were involved in the sucrose binding and splitting as well as transfructosylation activity. A catalytic comparison of Lsc of S. chungbukense DJ77 with the results of site-directed mutational analysis indicated that Gln275 may coordinate a favorable substrate binding environment, offering broad pH resistance in the range of 5-10. The results suggest that the recombinant E. coli carrying S. chungbukense DJ77 Lsc might produce levan under the regular growth conditions with less need for pH manipulation.
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Affiliation(s)
- Soo Youn Lee
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
- Climate Change Research Division, Korea Institute of Energy Research, 152 Gajeong-Ro, Yuseong-Gu, Daejeon 34129, Korea
| | - Woo-Ri Shin
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
| | - Simranjeet Singh Sekhon
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
| | - Jin-Pyo Lee
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
| | - Young-Chang Kim
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
| | - Ji-Young Ahn
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
| | - Yang-Hoon Kim
- School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, Korea
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Versluys M, Kirtel O, Toksoy Öner E, Van den Ende W. The fructan syndrome: Evolutionary aspects and common themes among plants and microbes. PLANT, CELL & ENVIRONMENT 2018; 41:16-38. [PMID: 28925070 DOI: 10.1111/pce.13070] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/30/2017] [Accepted: 09/09/2017] [Indexed: 05/13/2023]
Abstract
Fructans are multifunctional fructose-based water soluble carbohydrates found in all biological kingdoms but not in animals. Most research has focused on plant and microbial fructans and has received a growing interest because of their practical applications. Nevertheless, the origin of fructan production, the so-called "fructan syndrome," is still unknown. Why fructans only occur in a limited number of plant and microbial species remains unclear. In this review, we provide an overview of plant and microbial fructan research with a focus on fructans as an adaptation to the environment and their role in (a)biotic stress tolerance. The taxonomical and biogeographical distribution of fructans in both kingdoms is discussed and linked (where possible) to environmental factors. Overall, the fructan syndrome may be related to water scarcity and differences in physicochemical properties, for instance, water retaining characteristics, at least partially explain why different fructan types with different branching levels are found in different species. Although a close correlation between environmental stresses and fructan production is quite clear in plants, this link seems to be missing in microbes. We hypothesize that this can be at least partially explained by differential evolutionary timeframes for plants and microbes, combined with potential redundancy effects.
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Affiliation(s)
- Maxime Versluys
- Laboratory of Molecular Plant Biology, KU Leuven, Leuven, Belgium
| | - Onur Kirtel
- Industrial Biotechnology and Systems Biology Research Group, Bioengineering Department, Marmara University, Istanbul, 34722, Turkey
| | - Ebru Toksoy Öner
- Industrial Biotechnology and Systems Biology Research Group, Bioengineering Department, Marmara University, Istanbul, 34722, Turkey
| | - Wim Van den Ende
- Laboratory of Molecular Plant Biology, KU Leuven, Leuven, Belgium
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Ua-Arak T, Jakob F, Vogel RF. Influence of levan-producing acetic acid bacteria on buckwheat-sourdough breads. Food Microbiol 2017; 65:95-104. [DOI: 10.1016/j.fm.2017.02.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 02/02/2017] [Accepted: 02/03/2017] [Indexed: 11/28/2022]
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25
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Miranda-Molina A, Castillo E, Lopez Munguia A. A novel two-step enzymatic synthesis of blastose, a β-d-fructofuranosyl-(2↔6)-d-glucopyranose sucrose analogue. Food Chem 2017; 227:202-210. [DOI: 10.1016/j.foodchem.2017.01.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/12/2017] [Accepted: 01/17/2017] [Indexed: 11/29/2022]
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26
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Ua-Arak T, Jakob F, Vogel RF. Fermentation pH Modulates the Size Distributions and Functional Properties of Gluconobacter albidus TMW 2.1191 Levan. Front Microbiol 2017; 8:807. [PMID: 28522999 PMCID: PMC5415625 DOI: 10.3389/fmicb.2017.00807] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/19/2017] [Indexed: 11/13/2022] Open
Abstract
Bacterial levan has gained an increasing interest over the last decades due to its unique characteristics and multiple possible applications. Levan and other exopolysaccharides (EPSs) production are usually optimized to obtain the highest concentration or yield while a possible change of the molecular size and mass during the production process is mostly neglected. In this study, the molar mass and radius of levan samples were monitored during fermentations with the food-grade, levan-producing acetic acid bacterium Gluconobacter (G.) albidus TMW 2.1191 in shake flasks (without pH control) and bioreactors (with pH control at 4.5, 5.5 and 6.5, respectively). In uncontrolled fermentations, the levan size/molar mass continuously decreased concomitantly with the continuous acidification of the nutrient medium. On the contrary, the amount, molar mass and size of levan could be directly influenced by controlling the pH during fermentation. Using equal initial substrate amounts, the largest weight average molar mass and geometric radius of levan were observed at constant pH 6.5, while the highest levan concentration was obtained at constant pH 4.5. Since there is a special demand to find suitable hydrocolloids from food-grade bacteria to develop novel gluten-free (GF) products, these differently produced levans were used for baking of GF breads, and the best quality improvement was obtained by addition of levan with the highest mass and radius. This work, therefore, demonstrates for the first time that one bacterial strain can produce specific high molecular weight fractions of one EPS type, which differ in properties and sizes among each other in dependence of the controllable production conditions.
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Affiliation(s)
- Tharalinee Ua-Arak
- Lehrstuhl für Technische Mikrobiologie, Technische Universität MünchenFreising, Germany
| | - Frank Jakob
- Lehrstuhl für Technische Mikrobiologie, Technische Universität MünchenFreising, Germany
| | - Rudi F Vogel
- Lehrstuhl für Technische Mikrobiologie, Technische Universität MünchenFreising, Germany
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Öner ET, Hernández L, Combie J. Review of Levan polysaccharide: From a century of past experiences to future prospects. Biotechnol Adv 2016; 34:827-844. [DOI: 10.1016/j.biotechadv.2016.05.002] [Citation(s) in RCA: 203] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 05/01/2016] [Accepted: 05/04/2016] [Indexed: 01/24/2023]
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28
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Falconer RJ. Applications of isothermal titration calorimetry - the research and technical developments from 2011 to 2015. J Mol Recognit 2016; 29:504-15. [PMID: 27221459 DOI: 10.1002/jmr.2550] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/05/2016] [Accepted: 04/14/2016] [Indexed: 12/12/2022]
Abstract
Isothermal titration calorimetry is a widely used biophysical technique for studying the formation or dissociation of molecular complexes. Over the last 5 years, much work has been published on the interpretation of isothermal titration calorimetry (ITC) data for single binding and multiple binding sites. As over 80% of ITC papers are on macromolecules of biological origin, this interpretation is challenging. Some researchers have attempted to link the thermodynamics constants to events at the molecular level. This review highlights work carried out using binding sites characterized using x-ray crystallography techniques that allow speculation about individual bond formation and the displacement of individual water molecules during ligand binding and link these events to the thermodynamic constants for binding. The review also considers research conducted with synthetic binding partners where specific binding events like anion-π and π-π interactions were studied. The revival of assays that enable both thermodynamic and kinetic information to be collected from ITC data is highlighted. Lastly, published criticism of ITC research from a physical chemistry perspective is appraised and practical advice provided for researchers unfamiliar with thermodynamics and its interpretation. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Robert J Falconer
- Department of Chemical and Biological Engineering, ChELSI Institute, University of Sheffield, Sheffield, S1 3JD, UK.
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Santos-Moriano P, Monsalve-Ledesma L, Ortega-Muñoz M, Fernandez-Arrojo L, Ballesteros AO, Santoyo-Gonzalez F, Plou FJ. Vinyl sulfone-activated silica for efficient covalent immobilization of alkaline unstable enzymes: application to levansucrase for fructooligosaccharide synthesis. RSC Adv 2016. [DOI: 10.1039/c6ra14046g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Vinyl sulfone-silica was efficient to covalently immobilize levansucrase at neutral pH. LEV-VS showed altered selectivity towards FOS and good operational stability.
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Affiliation(s)
| | | | | | | | | | | | - F. J. Plou
- Instituto de Catalisis y Petroleoquimica
- CSIC
- 28049 Madrid
- Spain
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