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Kato H, Sakuta M, Tsunoda T, Nakashima Y, Morita H, Ogasawara Y, Dairi T. Peptide Epimerase Responsible for d-Amino Acid Introduction in Poly-γ-glutamic Acid Biosynthesis. Biomacromolecules 2024; 25:349-354. [PMID: 38095677 DOI: 10.1021/acs.biomac.3c01000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Poly-γ-glutamic acid (PGA) is a natural polymer of d- and/or l-glutamic acid (Glu) linked by isopeptide bonds. We recently showed that PGA synthetase, an enzyme complex composed of PgsB, PgsC, and PgsA, uses only l-Glu for polymerization, and d-Glu residues are introduced by peptide epimerization. However, it remains unclear which of the three enzymes is responsible for epimerization because in vitro functional characterization of the membrane-associated PgsBCA complex has never been successful. Here, we performed gene exchange experiments and showed that PgsA is responsible for the epimerization. Additionally, we identified a region in PgsA that modulates epimerization activity based on homology modeling from the recently solved structure of MslH, which showed 53% identity to PgsA. Our results suggested that d/l-ratios of the PGA product can be altered by introducing amino acid substitutions in this region, which will be useful for the production of PGA with controlled d/l-ratios.
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Affiliation(s)
- Hinata Kato
- Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Moeka Sakuta
- Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Takeshi Tsunoda
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Yu Nakashima
- Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Hiroyuki Morita
- Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Yasushi Ogasawara
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Tohru Dairi
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
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Parati M, Philip C, Mendrek B, Townrow D, Khalil I, Tchuenbou-Magaia F, Stanley M, Kowalczuk M, Adamus G, Radecka I. A circular bioprocess application of algal-based substrate for Bacillus subtilis natto production of γ-PGA. Front Chem 2023; 11:1158147. [PMID: 37153520 PMCID: PMC10158937 DOI: 10.3389/fchem.2023.1158147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is a bio-derived water-soluble, edible, hydrating, non-immunogenic polymer. Bacillus subtilis natto is a wild-type γ-PGA producer originally isolated from Japanese fermented natto beans whose activity has been shown to be enhanced through ion-specific activation of Extrachromosomal DNA maintenance mechanisms. Being a GRAS γ-PGA producer, this microorganism has attracted great interest in its use within an industrial context. Here we successfully synthesised amorphous, crystalline and semi-crystalline γ-PGA between 11-27 g/L. In line with circular economy principles, scalable macroalgal biomass has been evaluated as substrate for γ-PGA, displaying great potential in both yields and material composition. In this study whole cell, freeze dried seaweed -namely Laminaria digitata, Saccharina latissima and Alaria esculenta-were pre-treated by means of mechanical methods, sterilised and subsequently inoculated with B. subtilis natto. High shear mixing was found to be the most suitable pre-treatment technique. Supplemented L. digitata (9.1 g/L), S. latissima (10.2 g/L), A. esculenta (13 g/L) displayed γ-PGA yields comparable to those of standard GS media (14.4 g/L). Greatest yields of pure γ-PGA were obtained during the month of June for L. digitata (Avg. 4.76 g/L) comparable to those obtained with GS media (7.0 g/L). Further, pre-treated S. latissima and L. digitata complex media enabled for high molar mass (4,500 kDa) γ-PGA biosynthesis at 8.6 and 8.7 g/L respectively. Compared to standard GS media, algal derived γ-PGA displayed significantly higher molar masses. Further studies will be necessary to further evaluate the impact of varying ash contents upon the stereochemical properties and modify the properties of algal media based γ-PGA with the aid of key nutrients; however, the material synthesised to date can directly displace a number of fossil fuel derived chemicals in drug delivery applications, cosmetics, bioremediation, wastewater treatment, flocculation and as cryoprotectants.
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Affiliation(s)
- Mattia Parati
- Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, United Kingdom
- *Correspondence: Mattia Parati, ; Iza Radecka,
| | - Catherine Philip
- Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, United Kingdom
| | - Barbara Mendrek
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Zabrze, Poland
| | - David Townrow
- Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, United Kingdom
| | - Ibrahim Khalil
- Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, United Kingdom
| | | | - Michele Stanley
- Scottish Association for Marine Sciences, Oban, United Kingdom
| | - Marek Kowalczuk
- Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, United Kingdom
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Zabrze, Poland
| | - Grazyna Adamus
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Zabrze, Poland
| | - Iza Radecka
- Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, United Kingdom
- *Correspondence: Mattia Parati, ; Iza Radecka,
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Parati M, Khalil I, Tchuenbou-Magaia F, Adamus G, Mendrek B, Hill R, Radecka I. Building a circular economy around poly(D/L-γ-glutamic acid)- a smart microbial biopolymer. Biotechnol Adv 2022; 61:108049. [DOI: 10.1016/j.biotechadv.2022.108049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 11/26/2022]
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Microbial Poly-γ-Glutamic Acid (γ-PGA) as an Effective Tooth Enamel Protectant. Polymers (Basel) 2022; 14:polym14142937. [PMID: 35890712 PMCID: PMC9317725 DOI: 10.3390/polym14142937] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/12/2022] [Accepted: 07/16/2022] [Indexed: 02/07/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is a bio-derived water-soluble, edible, non-immunogenic nylon-like polymer with the biochemical characteristics of a polypeptide. This Bacillus-derived material has great potential for a wide range of applications, from bioremediation to tunable drug delivery systems. In the context of oral care, γ-PGA holds great promise in enamel demineralisation prevention. The salivary protein statherin has previously been shown to protect tooth enamel from acid dissolution and act as a reservoir for free calcium ions within oral cavities. Its superb enamel-binding capacity is attributed to the L-glutamic acid residues of this 5380 Da protein. In this study, γ-PGA was successfully synthesised from Bacillus subtilis natto cultivated on supplemented algae media and standard commercial media. The polymers obtained were tested for their potential to inhibit demineralisation of hydroxyapatite (HAp) when exposed to caries simulating acidic conditions. Formulations presenting 0.1, 0.25, 0.5, 0.75, 1, 2, 3 and 4% (w/v) γ-PGA concentration were assessed to determine the optimal conditions. Our data suggests that both the concentration and the molar mass of the γ-PGA were significant in enamel protection (p = 0.028 and p < 0.01 respectively). Ion Selective Electrode, combined with Fourier Transform Infra-Red studies, were employed to quantify enamel protection capacity of γ-PGA. All concentrations tested showed an inhibitory effect on the dissolution rate of calcium ions from hydroxyapatite, with 1% (wt) and 2% (wt) concentrations being the most effective. The impact of the average molar mass (M) on enamel dissolution was also investigated by employing commercial 66 kDa, 166 kDa, 440 kDa and 520 kDa γ-PGA fractions. All γ-PGA solutions adhered to the surface of HAp with evidence that this remained after 60 min of continuous acidic challenge. Inductively Coupled Plasma analysis showed a significant abundance of calcium ions associated with γ-PGA, which suggests that this material could also act as a responsive calcium delivery system. We have concluded that all γ-PGA samples tested (commercial and algae derived) display enamel protection capacity regardless of their concentration or average molar mass. However, we believe that γ-PGA D/L ratios might affect the binding more than its molar mass.
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Fujimoto Z, Hong LTT, Kishine N, Suzuki N, Kimura K. Tetramer formation of Bacillus subtilis YabJ protein that belongs to YjgF/YER057c/UK114 family. Biosci Biotechnol Biochem 2021; 85:297-306. [PMID: 33590041 DOI: 10.1093/bbb/zbaa037] [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: 07/08/2020] [Accepted: 09/23/2020] [Indexed: 11/12/2022]
Abstract
Bacillus subtilis YabJ protein belongs to the highly conserved YjgF/YER057c/UK114 family, which has a homotrimeric quaternary structure. The dominant allele of yabJ gene that is caused by a single amino acid mutation of Ser103Phe enables poly-γ-glutamic acid (γPGA) production of B. subtilis under conditions where the cell-density signal transduction was disturbed by the loss of DegQ function. X-ray crystallography of recombinant proteins revealed that unlike the homotrimeric wild-type YabJ, the mutant YabJ(Ser103Phe) had a homotetrameric quaternary structure, and the structural change appeared to be triggered by an inversion of the fifth β-strand. The YabJ homotetramer has a hole that is highly accessible, penetrating through the tetramer, and 2 surface concaves as potential ligand-binding sites. Western blot analyses revealed that the conformational change was also induced in vivo by the Ser103Phe mutation.
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Affiliation(s)
- Zui Fujimoto
- Advanced Analysis Center, National Agriculture and Food Research Organization (NAAC/NARO), Tsukuba, Ibaraki, Japan
| | - Le Thi Thu Hong
- Food Research Institute, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Ibaraki, Japan
| | - Naomi Kishine
- Advanced Analysis Center, National Agriculture and Food Research Organization (NAAC/NARO), Tsukuba, Ibaraki, Japan
| | - Nobuhiro Suzuki
- Advanced Analysis Center, National Agriculture and Food Research Organization (NAAC/NARO), Tsukuba, Ibaraki, Japan.,Institute of Material Structure Science, High Energy Accelerator Research Organization, KEK, Tsukuba, Ibaraki, Japan
| | - Keitarou Kimura
- Food Research Institute, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Ibaraki, Japan
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Poly-γ-glutamic acid production by Bacillus subtilis 168 using glucose as the sole carbon source: A metabolomic analysis. J Biosci Bioeng 2020; 130:272-282. [DOI: 10.1016/j.jbiosc.2020.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/22/2020] [Accepted: 04/26/2020] [Indexed: 11/18/2022]
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Wang D, Kim H, Lee S, Kim DH, Joe MH. High-level production of poly-γ-glutamic acid from untreated molasses by Bacillus siamensis IR10. Microb Cell Fact 2020; 19:101. [PMID: 32398084 PMCID: PMC7216703 DOI: 10.1186/s12934-020-01361-w] [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: 03/08/2020] [Accepted: 04/30/2020] [Indexed: 01/01/2023] Open
Abstract
Background Poly-γ-glutamic acid (γ-PGA) is a promising biopolymer and has been applied in many fields. Bacillus siamensis SB1001 was a newly isolated poly-γ-glutamic acid producer with sucrose as its optimal carbon source. To improve the utilization of carbon source, and then molasses can be effectively used for γ-PGA production, 60cobalt gamma rays was used to mutate the genes of B. siamensis SB1001. Results Bacillus siamensis IR10 was screened for the production of γ-PGA from untreated molasses. In batch fermentation, 17.86 ± 0.97 g/L γ-PGA was obtained after 15 h, which is 52.51% higher than that of its parent strain. Fed-batch fermentation was performed to further improve the yield of γ-PGA with untreated molasses, yielding 41.40 ± 2.01 g/L of γ-PGA with a productivity of 1.73 ± 0.08 g/L/h. An average γ-PGA productivity of 1.85 g/L/h was achieved in the repeated fed-batch fermentation. This is the first report of such a high γ-PGA productivity. The analysis of the enzyme activities showed that they were affected by the carbon sources, enhanced ICDH and GDH, and decreased ODHC, which are important for γ-PGA production. Conclusion These results suggest that untreated molasses can be used for economical and industrial-scale production of γ-PGA by B. siamensis IR10.![]()
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Affiliation(s)
- Dexin Wang
- Radiation Utilization and Facilities Management Division, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, 56212, Republic of Korea.,Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics,Center for Fungal Pathogenesis, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Hyangmi Kim
- Bacteria Research Team, Nakdonggang National Institute of Biological Resources (NNIBR), Sangju, 37242, Republic of Korea
| | - Sungbeom Lee
- Radiation Research Division, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, 56212, Republic of Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Dae-Hyuk Kim
- Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics,Center for Fungal Pathogenesis, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Min-Ho Joe
- Radiation Utilization and Facilities Management Division, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, 56212, Republic of Korea.
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Halmschlag B, Steurer X, Putri SP, Fukusaki E, Blank LM. Tailor-made poly-γ-glutamic acid production. Metab Eng 2019; 55:239-248. [DOI: 10.1016/j.ymben.2019.07.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/16/2019] [Accepted: 07/20/2019] [Indexed: 10/26/2022]
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Ojima Y, Kobayashi J, Doi T, Azuma M. Knockout of pgdS and ggt gene changes poly-γ-glutamic acid production in Bacillus licheniformis RK14-46. J Biotechnol 2019; 304:57-62. [PMID: 31404564 DOI: 10.1016/j.jbiotec.2019.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/11/2019] [Accepted: 08/05/2019] [Indexed: 12/31/2022]
Abstract
Poly-gamma-glutamic acid (γ-PGA) is a water-soluble, nontoxic biocompatible polymer, which is extensively used in medicines, foodstuffs, cosmetics, and in water treatment. We previously isolated a novel γ-PGA producing strain Bacillus licheniformis RK14 from soil and developed a hyper-producing mutant strain RK14-46 by an ethyl methanesulfonate (EMS) treatment. In this study, endo-type (pgdS) and exo-type γ-PGA hydrolases (ggt) were disrupted by integrating plasmids into the genomic DNA of B. licheniformis RK14-46 strain. Unexpectedly, we observed strong inhibition of γ-PGA production following deletion of the pgdS gene, suggesting that pgdS is essential for γ-PGA biosynthesis in strain RK14-46, and in its parent strain RK14. In contrast, γ-PGA production increased by the deletion of the ggt gene and reached 39 g/L in the presence of 90 g/L glucose and elevated oxygen supply. Furthermore, γ-PGA from the ggt-disrupted mutant (Δggt) maintained a larger molecular mass throughout the culture period, whereas that from the original RK14-46 strain had degraded after glucose consumption. γ-PGA-containing culture supernatants from Δggt strain showed greater flocculation efficiency in sewage sludge than supernatants from the RK14-46 strain, reflecting greater production of γ-PGA with larger molecular mass by the Δggt strain. This is the first report concerning the deletion of pgdS and ggt genes in B. licheniformis strain and the properties of γ-PGA obtained from the mutant strain.
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Affiliation(s)
- Yoshihiro Ojima
- Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Joji Kobayashi
- Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Takeru Doi
- Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Masayuki Azuma
- Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
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Hong LTT, Hachiya T, Hase S, Shiwa Y, Yoshikawa H, Sakakibara Y, Nguyen SLT, Kimura K. Poly-γ-glutamic acid production of Bacillus subtilis (natto) in the absence of DegQ: A gain-of-function mutation in yabJ gene. J Biosci Bioeng 2019; 128:690-696. [PMID: 31272833 DOI: 10.1016/j.jbiosc.2019.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 05/21/2019] [Accepted: 05/27/2019] [Indexed: 02/06/2023]
Abstract
Poly-γ-glutamic acid (γPGA) production by Bacillus subtilis is regulated by the quorum sensing system where DegQ transmits the cell density signal to a DNA-binding protein DegU. A mutation suppressing the γPGA-negative phenotype of degQ gene knock-out mutant (ΔdegQ) was identified through whole genome sequencing. The mutation conferred an amino acid substitution of Ser103 to phenylalanine (S103F) in yabJ that belongs to the highly conserved YjgF/YER057c/UK114 family. Genetic experiments including LacZ-fusion assay of γPGA synthetic operon confirmed that the suppressor mutation (yabJS103F) was responsible for the recovery of γPGA production. The yabJ itself was not essential for the γPGA production and the mutant allele enabled γPGA production of the ΔdegQ strain even in the presence of wild type yabJ. Thus, yabJS103F was a dominant positive allele. degU-lacZ fusion gene was hyper-expressed in cells carrying the yabJS103F, but disruption of yabJ did not affect the transcription level of the degU-lacZ. These observations suggested that YabJ acquired a function to stimulate expression of degU by the S103F mutation which is involved in the regulation of γPGA synthesis.
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Affiliation(s)
- Le Thi Thu Hong
- Food Research Institute, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Ibaraki 305-8642, Japan
| | - Tsuyoshi Hachiya
- Department of Bioscience and Informatics, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Sumitaka Hase
- Department of Bioscience and Informatics, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Yuh Shiwa
- Department of Molecular Microbiology, Tokyo University of Agriculture, Setagaya, Tokyo 156-8502, Japan
| | - Hirofumi Yoshikawa
- Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture, Setagaya, Tokyo 156-8502, Japan; Department of Bioscience, Tokyo University of Agriculture, Setagaya, Tokyo 156-8502, Japan
| | - Yasubumi Sakakibara
- Department of Bioscience and Informatics, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Sy Le Thanh Nguyen
- Food Research Institute, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Ibaraki 305-8642, Japan
| | - Keitarou Kimura
- Food Research Institute, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Ibaraki 305-8642, Japan.
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Coherent Aspects of Multifaceted Eco-friendly Biopolymer - Polyglutamic Acid from the Microbes. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2019. [DOI: 10.22207/jpam.13.2.10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Deciphering metabolic responses of biosurfactant lichenysin on biosynthesis of poly-γ-glutamic acid. Appl Microbiol Biotechnol 2019; 103:4003-4015. [PMID: 30923871 DOI: 10.1007/s00253-019-09750-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 01/21/2019] [Accepted: 03/06/2019] [Indexed: 12/19/2022]
Abstract
Poly-γ-glutamic acid (γ-PGA) is an extracellularly produced biodegradable polymer, which has been widely used as agricultural fertilizer, mineral fortifier, cosmetic moisturizer, and drug carrier. This study firstly discovered that lichenysin, as a biosurfactant, showed the capability to enhance γ-PGA production in Bacillus licheniformis. The exogenous addition of lichenysin improved the γ-PGA yield up to 17.9% and 21.9%, respectively, in the native strain B. licheniformis WX-02 and the lichenysin-deficient strain B. licheniformis WX02-ΔlchAC. The capability of intracellular biosynthesis of lichenysin was positively correlated with γ-PGA production. The yield of γ-PGA increased by 25.1% in the lichenysin-enhanced strain B. licheniformis WX02-Psrflch and decreased by 12.2% in the lichenysin-deficient strain WX02-ΔlchAC. Analysis of key enzyme activities and gene expression in the TCA cycle, precursor glutamate synthesis, and γ-PGA synthesis pathway revealed that the existence of lichenysin led to increased γ-PGA via shifting the carbon flux in the TCA cycle towards glutamate and γ-PGA biosynthetic pathways, minimizing by-product formation, and facilitating the uptake of extracellular substrates and the polymerization of glutamate to γ-PGA. Insight into the mechanisms of enhanced production of γ-PGA by lichenysin would define the essential parameters involved in γ-PGA biosynthesis and provide the basis for large-scale production of γ-PGA.
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Lee JM, Kim JH, Kim KW, Lee BJ, Kim DG, Kim YO, Lee JH, Kong IS. Physicochemical properties, production, and biological functionality of poly-γ-d-glutamic acid with constant molecular weight from halotolerant Bacillus sp. SJ-10. Int J Biol Macromol 2018; 108:598-607. [DOI: 10.1016/j.ijbiomac.2017.12.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/25/2017] [Accepted: 12/08/2017] [Indexed: 12/13/2022]
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Hsueh YH, Huang KY, Kunene SC, Lee TY. Poly-γ-glutamic Acid Synthesis, Gene Regulation, Phylogenetic Relationships, and Role in Fermentation. Int J Mol Sci 2017; 18:E2644. [PMID: 29215550 PMCID: PMC5751247 DOI: 10.3390/ijms18122644] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 02/03/2023] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) is a biodegradable biopolymer produced by several bacteria, including Bacillus subtilis and other Bacillus species; it has good biocompatibility, is non-toxic, and has various potential biological applications in the food, pharmaceutical, cosmetic, and other industries. In this review, we have described the mechanisms of γ-PGA synthesis and gene regulation, its role in fermentation, and the phylogenetic relationships among various pgsBCAE, a biosynthesis gene cluster of γ-PGA, and pgdS, a degradation gene of γ-PGA. We also discuss potential applications of γ-PGA and highlight the established genetic recombinant bacterial strains that produce high levels of γ-PGA, which can be useful for large-scale γ-PGA production.
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Affiliation(s)
- Yi-Huang Hsueh
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan city 32003, Taiwan.
| | - Kai-Yao Huang
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan city 32003, Taiwan.
- Department of Medical Research, Hsinchu Mackay Memorial Hospital, Hsinchu city 300, Taiwan.
| | - Sikhumbuzo Charles Kunene
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan city 32003, Taiwan.
| | - Tzong-Yi Lee
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan city 32003, Taiwan.
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Liu T, Yamashita K, Fukumoto Y, Tachibana T, Azuma M. Flocculation of Real Sewage Sludge Using Poly-γ-glutamic Acid Produced by Bacillus sp. Isolated from Soil. JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 2017. [DOI: 10.1252/jcej.16we158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tao Liu
- Department of Applied Chemistry and Bioengineering, Osaka City University
| | - Kyouhei Yamashita
- Department of Applied Chemistry and Bioengineering, Osaka City University
| | | | - Taro Tachibana
- Department of Applied Chemistry and Bioengineering, Osaka City University
| | - Masayuki Azuma
- Department of Applied Chemistry and Bioengineering, Osaka City University
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Simultaneous Biosynthesis of Polyhydroxyalkanoates and Extracellular Polymeric Substance (EPS) from Crude Glycerol from Biodiesel Production by Different Bacterial Strains. Appl Biochem Biotechnol 2016; 180:1110-1127. [DOI: 10.1007/s12010-016-2155-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/01/2016] [Indexed: 02/04/2023]
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17
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Guo J, Cheng G, Gou XY, Xing F, Li S, Han YC, Wang L, Song JM, Shu CC, Chen SW, Chen LL. Comprehensive transcriptome and improved genome annotation ofBacillus licheniformisWX-02. FEBS Lett 2015; 589:2372-81. [DOI: 10.1016/j.febslet.2015.07.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 07/11/2015] [Accepted: 07/20/2015] [Indexed: 01/10/2023]
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Kumar S, Shah AK. Characterization of an adhesive molecule from Bacillus megaterium ADE-0-1. Carbohydr Polym 2014; 117:543-548. [PMID: 25498669 DOI: 10.1016/j.carbpol.2014.10.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/22/2014] [Accepted: 10/10/2014] [Indexed: 11/17/2022]
Abstract
An adhesive exopolysaccharide (EPS), from a biofilm forming marine strain ADE-0-1, identified as Bacillus megaterium using conventional microbiological test and 16S rDNA analysis, contained 75% carbohydrate, 17% uronic acid and 0.00125% pyruvate on dry weight basis as per colorimetric determinations and found anionic in nature by ion exchange chromatography. Paper chromatographic and HPLC analysis of EPS hydrolysate indicated presence of arabinose, glucose, mannose, galacturonic acid and glucuronic acid. Its molecular weight was 0.5×10(6) Da, by gel permeation chromatography. FT-IR spectroscopic analysis of EPS revealed presence of hydroxyl and carboxyl groups particularly. EPS exhibited an adhesive nature and could glue wood, metals and acrylic plastic. Using this EPS adhesive (10% w/v), maximum lap shear strength observed was 6.12 MPa at pH 7 and 50 °C (curing temperature) for wood to wood specimen as compared to 6.54 MPa obtained with fevicol (48 to 50% w/v).
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Affiliation(s)
- Santosh Kumar
- Department of Microbiology and Biotechnology Centre, Faculty of Science, The M. S. University of Baroda, Sayajiganj, Baroda 390002, Gujarat, India.
| | - Avinash K Shah
- Department of Microbiology and Biotechnology Centre, Faculty of Science, The M. S. University of Baroda, Sayajiganj, Baroda 390002, Gujarat, India.
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19
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Zeng W, Chen G, Wang Q, Zheng S, Shu L, Liang Z. Metabolic studies of temperature control strategy on poly(γ-glutamic acid) production in a thermophilic strain Bacillus subtilis GXA-28. BIORESOURCE TECHNOLOGY 2014; 155:104-110. [PMID: 24434700 DOI: 10.1016/j.biortech.2013.12.086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/13/2013] [Accepted: 12/18/2013] [Indexed: 06/03/2023]
Abstract
A thermophilic strain Bacillus subtilis GXA-28 with capability of γ-PGA production was characterized, and its product was identified. The effect of temperatures on cell growth, γ-PGA yield and molecular weight were investigated. Results showed that γ-PGA yield reached 19.92g/L at 45°C with a high productivity of 0.91g/L/h, and the molecular weight reached 3.03×10(6)Da. Then, the flux distribution and the key enzyme activities at 2-oxoglutarate branch under specified temperature were determined to illustrate the possible metabolic mechanism contributing to the improved γ-PGA production. Results indicated that the fluxes from iso-citrate to 2-oxoglutarate and from 2-oxoglutarate to glutamate were increased with high activity of isocitrate dehydrogenase and glutamate dehydrogenase, which led to enhance γ-PGA production. This work firstly employed temperature control strategy to improve γ-PGA production, and provided novel information on the metabolic mechanism of γ-PGA biosynthesis in Bacillus species.
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Affiliation(s)
- Wei Zeng
- Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning 530004, Guangxi, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, Guangxi, China; College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Guiguang Chen
- College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Qinglong Wang
- College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Shuangfeng Zheng
- Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning 530004, Guangxi, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, Guangxi, China; College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Lin Shu
- College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Zhiqun Liang
- Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, Nanning 530004, Guangxi, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, Guangxi, China; College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China.
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20
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Ashiuchi M. Microbial production and chemical transformation of poly-γ-glutamate. Microb Biotechnol 2013; 6:664-74. [PMID: 23855427 PMCID: PMC3815933 DOI: 10.1111/1751-7915.12072] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/29/2013] [Accepted: 06/05/2013] [Indexed: 11/29/2022] Open
Abstract
Poly-γ-glutamate (PGA), a novel polyamide material with industrial applications, possesses a nylon-like backbone, is structurally similar to polyacrylic acid, is biodegradable and is safe for human consumption. PGA is frequently found in the mucilage of natto, a Japanese traditional fermented food. To date, three different types of PGA, namely a homo polymer of D-glutamate (D-PGA), a homo polymer of L-glutamate (L-PGA), and a random copolymer consisting of D- and L-glutamate (DL-PGA), are known. This review will detail the occurrence and physiology of PGA. The proposed reaction mechanism of PGA synthesis including its localization and the structure of the involved enzyme, PGA synthetase, are described. The occurrence of multiple carboxyl residues in PGA likely plays a role in its relative unsuitability for the development of bio-nylon plastics and thus, establishment of an efficient PGA-reforming strategy is of great importance. Aside from the potential applications of PGA proposed to date, a new technique for chemical transformation of PGA is also discussed. Finally, some techniques for PGA and its derivatives in advanced material technology are presented.
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Affiliation(s)
- Makoto Ashiuchi
- Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Nankoku, Kochi, 783-8502, Japan
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21
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Hamano Y, Arai T, Ashiuchi M, Kino K. NRPSs and amide ligases producing homopoly(amino acid)s and homooligo(amino acid)s. Nat Prod Rep 2013; 30:1087-97. [PMID: 23817633 DOI: 10.1039/c3np70025a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microorganisms are capable of producing a wide variety of biopolymers. Homopoly(amino acid)s and homooligo(amino acid)s, which are made up of only a single type of amino acid, are relatively rare; in fact, only two homopoly(amino acid)s have been known to occur in nature: poly(ε-L-lysine) (ε-PL) and poly(γ-glutamic acid) (γ-PGA). Bacterial enzymes that produce homooligo(amino acid)s, such as L-β-lysine-, L-valine-, L-leucine-, L-isoleucine-, L-methionine-, and L-glutamic acid-oligopeptides and poly(α-l-glutamic acid) (α-PGA) have recently been identified, as well as ε-PL synthetase and γ-PGA synthetase. This article reviews the current knowledge about these unique enzymes producing homopoly(amino acid)s and homooligo(amino acid)s.
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Affiliation(s)
- Yoshimitsu Hamano
- Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji-cho, Yoshida-gun, Fukui 910-1195, Japan.
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22
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Zhao C, Zhang Y, Wei X, Hu Z, Zhu F, Xu L, Luo M, Liu H. Production of ultra-high molecular weight poly-γ-glutamic acid with Bacillus licheniformis P-104 and characterization of its flocculation properties. Appl Biochem Biotechnol 2013; 170:562-72. [PMID: 23553109 DOI: 10.1007/s12010-013-0214-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 03/21/2013] [Indexed: 10/27/2022]
Abstract
A novel strain of Bacillus licheniformis P-104 was isolated from Chinese soybean paste to produce a bioflocculant. The bioflocculant was confirmed as ultra-high molecular weight poly-γ-glutamic acid (γ-PGA) using Fourier transform infrared spectrum, high-performance liquid chromatography, and gel permeation chromatography with multi-angle laser light scattering. The production technology and flocculation properties of γ-PGA were investigated. By fed-batch fermentation in a 7-L bioreactor, the maximum γ-PGA yield reached 41.6 g L(-1) with a productivity rate of 1.07 g L(-1) h(-1). The flocculating activity of γ-PGA for kaolin suspension was 33.5±1.6 1/OD under the optimized flocculation conditions (6 mM Ca(2+), 1.5 mg L(-1) γ-PGA, and pH 6.0). The optimized dosage of γ-PGA for flocculation was just about 30 % of that of reported γ-PGA produced by other strains. Moreover, the flocculation activity of γ-PGA produced by strain P-104 was much higher than commercial γ-PGA with the molecular weight ranging 200-500 kDa and 1,500-2,500 kDa. This study provided a promising strain and an efficient method for production of ultra-high molecular weight γ-PGA which could be used as a potential green bioflocculant.
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Affiliation(s)
- Caifeng Zhao
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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23
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Ashiuchi M. Analytical approaches to poly-γ-glutamate: Quantification, molecular size determination, and stereochemistry investigation. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3096-101. [DOI: 10.1016/j.jchromb.2011.03.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 03/15/2011] [Accepted: 03/17/2011] [Indexed: 11/27/2022]
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Borgmeier C, Biedendieck R, Hoffmann K, Jahn D, Meinhardt F. Transcriptome profiling of degU expression reveals unexpected regulatory patterns in Bacillus megaterium and discloses new targets for optimizing expression. Appl Microbiol Biotechnol 2011; 92:583-96. [PMID: 21935588 DOI: 10.1007/s00253-011-3575-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/17/2011] [Accepted: 09/08/2011] [Indexed: 11/24/2022]
Abstract
The first whole transcriptome assessment of a Bacillus megaterium strain provides unanticipated insights into the degSU regulon considered to be of central importance for exo-enzyme production. Regulatory patterns as well as the transcription of degSU itself deviate from the model organism Bacillus subtilis; the number of DegU-regulated secretory enzymes is rather small. Targets for productivity optimization, besides degSU itself, arise from the unexpected DegU-dependent induction of the transition-state regulator AbrB during exponential growth. Induction of secretion-assisting factors, such as the translocase subunit SecY or the signal peptidase SipM, promote hypersecretion. B. megaterium DegSU transcriptional control is advantageous for production purposes, since the degU32 constitutively active mutant conferred hypersecretion of a heterologous Bacillus amyloliquefaciens amylase without the detrimental rise, as for B. subtilis and Bacillus licheniformis, in extracellular proteolytic activities.
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Affiliation(s)
- Claudia Borgmeier
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms Universität, Corrensstrasse 3, 48149, Münster, Germany
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25
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Huang B, Qin P, Xu Z, Zhu R, Meng Y. Effects of CaCl2 on viscosity of culture broth, and on activities of enzymes around the 2-oxoglutarate branch, in Bacillus subtilis CGMCC 2108 producing poly-(γ-glutamic acid). BIORESOURCE TECHNOLOGY 2011; 102:3595-3598. [PMID: 21071211 DOI: 10.1016/j.biortech.2010.10.073] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 10/15/2010] [Accepted: 10/15/2010] [Indexed: 05/30/2023]
Abstract
CaCl(2) was used as a novel additive to enhance poly-(γ-glutamic acid) (γ-PGA) production by Bacillus subtilis strain CGMCC 2108. Addition of CaCl(2) to medium effectively reduced viscosity of culture broth, and increased consumption of extracellular glutamate by 11.4%, leading to γ-PGA yield of 9.07 g/l, compared to 7.88 g/l in control. CaCl(2) also increased activities of three key enzymes around the crucial 2-oxoglutarate branch of the γ-PGA biosynthesis pathway: isocitrate dehydrogenase (ICDH), glutamate dehydrogenase (GDH), and 2-oxoglutarate dehydrogenase complex (ODHC). In particular, GDH activity was increased more than 8-fold, indicating that more 2-oxoglutarate was directed to synthesis of glutamate, the substrate of γ-PGA. Interestingly, the molecular weight of γ-PGA remained constant regardless of CaCl(2) addition.
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Affiliation(s)
- Baiqi Huang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, PR China
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26
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Yamasaki D, Minouchi Y, Ashiuchi M. Extremolyte-like applicability of an archaeal exopolymer, poly-gamma-L-glutamate. ENVIRONMENTAL TECHNOLOGY 2010; 31:1129-1134. [PMID: 20718295 DOI: 10.1080/09593331003592279] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An extremely halophilic archaeon Natrialba aegyptiaca produces extracellular poly-gamma-glutamate (PGA), in which only L-glutamate is polymerized via gamma-amide linkages. We examined the extremolyte-like applicability of archaeal PGA and found the ameliorating effects of L-PGA on the resistibility to freeze-thawing and proteolysis, thermostability, and alkalotolerance of a model enzyme, labile DNA ligase. For example, the coexistence of low (e.g. 0.01 mg mL(-1)) and high (e.g. 0.1 mg mL(-1)) concentrations of L-PGA with an average molecular mass of 1000 kDa increased the midpoint of thermal inactivation of DNA ligase by about 15 degrees C and 18 degrees C, respectively, and the model enzyme further remained active even under extremely alkaline conditions of pH 11.4 in the presence of the high concentration of L-PGA. This is the first characterization of the stereo-regular PGA molecules as atypical extremolytes. L-PGA from extremophiles has great potential as a bio-based protectant (or stabilizer) with industrial versatility.
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Affiliation(s)
- Daisuke Yamasaki
- Graduate School of Agriculture, Kochi University, Nankoku, Kochi 783-8502, Japan
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27
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Occurrence and Biosynthetic Mechanism of Poly-Gamma-Glutamic Acid. AMINO-ACID HOMOPOLYMERS OCCURRING IN NATURE 2010. [DOI: 10.1007/978-3-642-12453-2_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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28
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Wei X, Ji Z, Chen S. Isolation of Halotolerant Bacillus licheniformis WX-02 and Regulatory Effects of Sodium Chloride on Yield and Molecular Sizes of Poly-γ-Glutamic Acid. Appl Biochem Biotechnol 2009; 160:1332-40. [DOI: 10.1007/s12010-009-8681-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Accepted: 05/20/2009] [Indexed: 11/24/2022]
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29
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Ashiuchi M, Nishikawa Y, Matsunaga K, Yamamoto M, Shimanouchi K, Misono H. Genetic design of conditional d-glutamate auxotrophy for Bacillus subtilis: Use of a vector-borne poly-γ-glutamate synthetic system. Biochem Biophys Res Commun 2007; 362:646-50. [PMID: 17720142 DOI: 10.1016/j.bbrc.2007.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Accepted: 08/03/2007] [Indexed: 11/26/2022]
Abstract
Bacillus subtilis possesses two glutamate racemase isozymes, RacE and YrpC. For the first time, we succeeded in constructing glutamate racemase-gene disruptants of B. subtilis. Phenotypic analysis of their D-glutamate auxotrophy indicated that the RacE-type glutamate racemase is important for ensuring maximum growth rate but dispensable. The YrpC-type glutamate racemase probably operates as an anaplerotic enzyme for RacE, especially under liquid culture conditions. We found novel applicability of RacE-less mutants inheriting only a marginal activity for endogenous D-glutamate supply, viz. the employment for the in vivo identification of D-glutamate-consuming systems. In fact, the genetic induction of a poly-gamma-glutamate synthetic system led a RacE-less mutant to severe growth suppression, which was overcome in the presence of a high concentration of exogenous D-glutamate. The results indicate that a significant amount of D-glutamate is consumed during poly-glutamate biosynthesis. To our knowledge, this is the first report of conditional D-glutamate auxotrophy for B. subtilis.
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Affiliation(s)
- Makoto Ashiuchi
- Department of Bioresources Science, Kochi University, Nankoku, Kochi 783-8502, Japan.
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