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Mol M, Ardila MS, Mol BA, Aliyu H, Neumann A, de Maayer P. The effects of synthesis gas feedstocks and oxygen perturbation on hydrogen production by Parageobacillus thermoglucosidasius. Microb Cell Fact 2024; 23:125. [PMID: 38698392 PMCID: PMC11064277 DOI: 10.1186/s12934-024-02391-4] [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: 03/01/2024] [Accepted: 04/12/2024] [Indexed: 05/05/2024] Open
Abstract
BACKGROUND The facultatively anaerobic thermophile Parageobacillus thermoglucosidasius is able to produce hydrogen gas (H2) through the water-gas shift (WGS) reaction. To date this process has been evaluated under controlled conditions, with gas feedstocks comprising carbon monoxide and variable proportions of air, nitrogen and hydrogen. Ultimately, an economically viable hydrogenogenic system would make use of industrial waste/synthesis gases that contain high levels of carbon monoxide, but which may also contain contaminants such as H2, oxygen (O2) and other impurities, which may be toxic to P. thermoglucosidasius. RESULTS We evaluated the effects of synthesis gas (syngas) mimetic feedstocks on WGS reaction-driven H2 gas production by P. thermoglucosidasius DSM 6285 in small-scale fermentations. Improved H2 gas production yields and faster onset towards hydrogen production were observed when anaerobic synthetic syngas feedstocks were used, at the expense of biomass accumulation. Furthermore, as the WGS reaction is an anoxygenic process, we evaluated the influence of O2 perturbation on P. thermoglucosidasius hydrogenogenesis. O2 supplementation improved biomass accumulation, but reduced hydrogen yields in accordance with the level of oxygen supplied. However, H2 gas production was observed at low O2 levels. Supplementation also induced rapid acetate consumption, likely to sustain growth. CONCLUSION The utilisation of anaerobic syngas mimetic gas feedstocks to produce H2 and the relative flexibility of the P. thermoglucosidasius WGS reaction system following O2 perturbation further supports its applicability towards more robust and continuous hydrogenogenic operation.
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Affiliation(s)
- Michael Mol
- School of Molecular and Cell Biology, Faculty of Science, University of the Witwatersrand, Johannesburg, 2000, South Africa
| | - Magda Stephania Ardila
- Section II: Electrobiotechnology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany
| | - Bronwyn Ashleigh Mol
- School of Molecular and Cell Biology, Faculty of Science, University of the Witwatersrand, Johannesburg, 2000, South Africa
| | - Habibu Aliyu
- Section II: Electrobiotechnology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany
| | - Anke Neumann
- Section II: Electrobiotechnology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.
| | - Pieter de Maayer
- School of Molecular and Cell Biology, Faculty of Science, University of the Witwatersrand, Johannesburg, 2000, South Africa.
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Paredes-Barrada M, Kopsiaftis P, Claassens NJ, van Kranenburg R. Parageobacillus thermoglucosidasius as an emerging thermophilic cell factory. Metab Eng 2024; 83:39-51. [PMID: 38490636 DOI: 10.1016/j.ymben.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/21/2024] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Abstract
Parageobacillus thermoglucosidasius is a thermophilic and facultatively anaerobic microbe, which is emerging as one of the most promising thermophilic model organisms for metabolic engineering. The use of thermophilic microorganisms for industrial bioprocesses provides the advantages of increased reaction rates and reduced cooling costs for bioreactors compared to their mesophilic counterparts. Moreover, it enables starch or lignocellulose degradation and fermentation to occur at the same temperature in a Simultaneous Saccharification and Fermentation (SSF) or Consolidated Bioprocessing (CBP) approach. Its natural hemicellulolytic capabilities and its ability to convert CO to metabolic energy make P. thermoglucosidasius a potentially attractive host for bio-based processes. It can effectively degrade hemicellulose due to a number of hydrolytic enzymes, carbohydrate transporters, and regulatory elements coded from a genomic cluster named Hemicellulose Utilization (HUS) locus. The growing availability of effective genetic engineering tools in P. thermoglucosidasius further starts to open up its potential as a versatile thermophilic cell factory. A number of strain engineering examples showcasing the potential of P. thermoglucosidasius as a microbial chassis for the production of bulk and fine chemicals are presented along with current research bottlenecks. Ultimately, this review provides a holistic overview of the distinct metabolic characteristics of P. thermoglucosidasius and discusses research focused on expanding the native metabolic boundaries for the development of industrially relevant strains.
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Affiliation(s)
- Miguel Paredes-Barrada
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | | | - Nico J Claassens
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands; Corbion, Arkelsedijk 46, 4206 AC, Gorinchem, The Netherlands.
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Liu J, Han X, Tao F, Xu P. Metabolic engineering of Geobacillus thermoglucosidasius for polymer-grade lactic acid production at high temperature. BIORESOURCE TECHNOLOGY 2024; 393:130164. [PMID: 38072074 DOI: 10.1016/j.biortech.2023.130164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 01/18/2024]
Abstract
The production and application of biodegradable polylactic acid are still severely hindered by the cost of its polymer-grade lactic acid monomers. High-temperature biomanufacturing has emerged as an increasingly attractive approach to enable low-cost and high-efficiency bulk chemical production. In this study, thermophilic Geobacillus thermoglucosidasius was reprogrammed to obtain optically pure l-lactic acid- and d-lactic acid-producing strains, G. thermoglucosidasius GTD17 and GTD7, by using rational metabolic engineering strategies including pathway construction, by-product elimination, and production enhancing. Moreover, semi-rational adaptive evolution was carried out to further improve their lactic acid synthesis performance. The final strains GTD17-55 and GTD7-144 produce 151.1 g/L of l-lactic acid and 153.1 g/L of d-lactic acid at 60 °C, respectively. In consideration of the high temperature, productive performance of these strains is superior compared to the state-of-the-art industrial strains. This study lays the foundation for the low-cost and efficient production of biodegradable plastic polylactic acid.
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Affiliation(s)
- Jiongqin Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiao Han
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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Basak A, Gavande PV, Murmu N, Ghosh S. Optimization and biochemical characterization of a thermotolerant processive cellulase, PtCel1, of Parageobacillus thermoglucosidasius NBCB1. J Basic Microbiol 2023; 63:326-339. [PMID: 36074980 DOI: 10.1002/jobm.202200394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/11/2022] [Accepted: 08/20/2022] [Indexed: 11/11/2022]
Abstract
Vermicomposting involves enrichment of microorganisms that are able to resist higher temperatures and perform simultaneous degradation of lignocellulose, and therefore, such microbial communities are a potential source of cellulolytic enzymes. This study aimed to optimize the production of a processive cellulase by Parageobacillus thermoglucosidasius NBCB1 isolated from vermicompost, under submerged fermentation of rice straw and to characterize the purified enzyme for industrial suitability. Cellulase production in basal medium (7.27 IU/mg) was enhanced to 61 IU/mg by One Factor At a Time approach, which was further improved to 78.46 IU/mg by genetic algorithm based artificial neural networking. The cellulase PtCel1 purified from bacterial culture showed a molecular weight of ≈33 kD, had activity on both crystalline (305 IU/mg) and amorphous (184 IU/mg) cellulose as substrates. It had pH and temperature optima of 5.5°C and 60°C, respectively, and retained 100% activity upon preincubation at 60°C for 1 h indicating thermostability. PtCel1 was tolerant to sodium dodecyl sulfate, glucose and mannose; and the various metal chlorides, such as sodium, magnesium, calcium and zinc, acted as inducers giving 77.54%, 45.15%, 61.10%, and 169.14% augmentation of activity, respectively. Its efficiency on cellulosic substrates and robustness against aforementioned chemical and thermal environment makes it suitable for industrial applications.
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Affiliation(s)
- Arijita Basak
- Department of Biotechnology, University of North Bengal, Raja Rammohunpur, Darjeeling, India
| | - Parmeshwar V Gavande
- Department of Biotechnology, University of North Bengal, Raja Rammohunpur, Darjeeling, India.,Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India
| | - Nensina Murmu
- Department of Biotechnology, University of North Bengal, Raja Rammohunpur, Darjeeling, India
| | - Shilpi Ghosh
- Department of Biotechnology, University of North Bengal, Raja Rammohunpur, Darjeeling, India
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Nagarajan D, Chen CY, Ariyadasa TU, Lee DJ, Chang JS. Macroalgal biomass as a potential resource for lactic acid fermentation. CHEMOSPHERE 2022; 309:136694. [PMID: 36206920 DOI: 10.1016/j.chemosphere.2022.136694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/25/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Lactic acid is an essential platform chemical with various applications in the chemicals, food, pharmaceutical, and cosmetic industries. Currently, the demand for lactic acid is driven by the role of lactic acid as the starting material for the production of bioplastic polylactide. Microbial fermentation for lactic acid production is favored due to the production of enantiomerically pure lactic acid required for polylactide synthesis, as opposed to the racemic mixture obtained via chemical synthesis. The utilization of first-generation feedstock for commercial lactic acid production is challenged by feedstock costs and sustainability issues. Macroalgae are photosynthetic benthic aquatic plants that contribute tremendously towards carbon capture with subsequent carbon-rich biomass production. Macroalgae are commercially cultivated to extract hydrocolloids, and recent studies have focused on applying biomass as a fermentation feedstock. This review provides comprehensive information on the design and development of sustainable and cost-effective, algae-based lactic acid production. The central carbon regulation in lactic acid bacteria and the metabolism of seaweed-derived sugars are described. An exhaustive compilation of lactic acid fermentation of macroalgae hydrolysates revealed that lactic acid bacteria can effectively ferment the mixture of sugars present in the hydrolysate with comparable yields. The environmental impacts and economic prospects of macroalgal lactic acid are analyzed. Valorization of the vast amounts of spent macroalgal biomass residue post hydrocolloid extraction in a biorefinery is a viable strategy for cost-effective lactic acid production.
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Affiliation(s)
- Dillirani Nagarajan
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.
| | - Chun-Yen Chen
- University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan; Research Center for Circular Economy, National Cheng Kung University, Tainan, Taiwan
| | - Thilini U Ariyadasa
- Department of Chemical and Process Engineering, Faculty of Engineering, University of Moratuwa, Moratuwa, 10400, Sri Lanka
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tang, Hong Kong
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan; Department of Chemical and Materials Engineering, Tunghai University, Taichung, 407, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, 407, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li, 32003, Taiwan.
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Liang J, van Kranenburg R, Bolhuis A, Leak DJ. Removing carbon catabolite repression in Parageobacillus thermoglucosidasius DSM 2542. Front Microbiol 2022; 13:985465. [PMID: 36338101 PMCID: PMC9631020 DOI: 10.3389/fmicb.2022.985465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 08/30/2022] [Indexed: 11/21/2022] Open
Abstract
Parageobacillus thermoglucosidasius is a thermophilic bacterium of interest for lignocellulosic biomass fermentation. However, carbon catabolite repression (CCR) hinders co-utilization of pentoses and hexoses in the biomass substrate. Hence, to optimize the fermentation process, it is critical to remove CCR in the fermentation strains with minimal fitness cost. In this study, we investigated whether CCR could be removed from P. thermoglucosidasius DSM 2542 by mutating the Ser46 regulatory sites on HPr and Crh to a non-reactive alanine residue. It was found that neither the ptsH1 (HPr-S46A) nor the crh1 (Crh-S46A) mutation individually eliminated CCR in P. thermoglucosidasius DSM 2542. However, it was not possible to generate a ptsH1 crh1 double mutant. While the Crh-S46A mutation had no obvious fitness effect in DSM 2542, the ptsH1 mutation had a negative impact on cell growth and sugar utilization under fermentative conditions. Under these conditions, the ptsH1 mutation was associated with the production of a brown pigment, believed to arise from methylglyoxal production, which is harmful to cells. Subsequently, a less directed adaptive evolution approach was employed, in which DSM 2542 was grown in a mixture of 2-deoxy-D-glucose(2-DG) and xylose. This successfully removed CCR from P. thermoglucosidasius DSM 2542. Two selection strategies were applied to optimize the phenotypes of evolved strains. Genome sequencing identified key mutations affecting the PTS components PtsI and PtsG, the ribose operon repressor RbsR and adenine phosphoribosyltransferase APRT. Genetic complementation and bioinformatics analysis revealed that the presence of wild type rbsR and apt inhibited xylose uptake or utilization, while ptsI and ptsG might play a role in the regulation of CCR in P. thermoglucosidasius DSM 2542.
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Affiliation(s)
- Jinghui Liang
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Centre for Sustainable and Circular Technologies (CSCT), University of Bath, Bath, United Kingdom
- *Correspondence: Jinghui Liang
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Wageningen, Netherlands
- Corbion, Gorinchem, Netherlands
| | - Albert Bolhuis
- Department of Pharmacy and Pharmacology, Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
| | - David J. Leak
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Centre for Sustainable and Circular Technologies (CSCT), University of Bath, Bath, United Kingdom
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