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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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Wu MH, Kao MR, Li CW, Yu SM, Ho THD. A unique self-truncation of bacterial GH5 endoglucanases leads to enhanced activity and thermostability. BMC Biol 2022; 20:137. [PMID: 35681203 PMCID: PMC9185962 DOI: 10.1186/s12915-022-01334-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 05/18/2022] [Indexed: 11/10/2022] Open
Abstract
Background β-1,4-endoglucanase (EG) is one of the three types of cellulases used in cellulose saccharification during lignocellulosic biofuel/biomaterial production. GsCelA is an EG secreted by the thermophilic bacterium Geobacillus sp. 70PC53 isolated from rice straw compost in southern Taiwan. This enzyme belongs to glycoside hydrolase family 5 (GH5) with a TIM-barrel structure common among all members of this family. GsCelA exhibits excellent lignocellulolytic activity and thermostability. In the course of investigating the regulation of this enzyme, it was fortuitously discovered that GsCelA undergoes a novel self-truncation/activation process that appears to be common among GH5 enzymes. Results Three diverse Gram-positive bacterial GH5 EGs, but not a GH12 EG, undergo an unexpected self-truncation process by removing a part of their C-terminal region. This unique process has been studied in detail with GsCelA. The purified recombinant GsCelA was capable of removing a 53-amino-acid peptide from the C-terminus. Natural or engineered GsCelA truncated variants, with up to 60-amino-acid deletion from the C-terminus, exhibited higher specific activity and thermostability than the full-length enzyme. Interestingly, the C-terminal part that is removed in this self-truncation process is capable of binding to cellulosic substrates of EGs. The protein truncation, which is pH and temperature dependent, occurred between amino acids 315 and 316, but removal of these two amino acids did not stop the process. Furthermore, mutations of E142A and E231A, which are essential for EG activity, did not affect the protein self-truncation process. Conversely, two single amino acid substitution mutations affected the self-truncation activity without much impact on EG activities. In Geobacillus sp. 70PC53, the full-length GsCelA was first synthesized in the cell but progressively transformed into the truncated form and eventually secreted. The GsCelA self-truncation was not affected by standard protease inhibitors, but could be suppressed by EDTA and EGTA and enhanced by certain divalent ions, such as Ca2+, Mg2+, and Cu2+. Conclusions This study reveals novel insights into the strategy of Gram-positive bacteria for directing their GH5 EGs to the substrate, and then releasing the catalytic part for enhanced activity via a spontaneous self-truncation process. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01334-y.
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Affiliation(s)
- Mei-Huey Wu
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China.,Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, Republic of China
| | - Mu-Rong Kao
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, Republic of China
| | - Chen-Wei Li
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, Republic of China
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, Republic of China. .,Biotechnology Research Center, National Chung Hsing University, Taichung, 402, Taiwan, Republic of China. .,Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan, Republic of China.
| | - Tuan-Hua David Ho
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China. .,Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, Republic of China. .,Biotechnology Research Center, National Chung Hsing University, Taichung, 402, Taiwan, Republic of China.
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Production Optimization and Biochemical Characterization of Cellulase from Geobacillus sp. KP43 Isolated from Hot Spring Water of Nepal. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6840409. [PMID: 35601142 PMCID: PMC9119783 DOI: 10.1155/2022/6840409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 04/11/2022] [Accepted: 04/16/2022] [Indexed: 11/25/2022]
Abstract
This study is aimed at isolating and identifying a thermophilic cellulolytic bacterium from hot spring water and characterizing thermostable cellulase produced by the isolate. Enrichment and culture of water sample was used for isolation of bacterial strains and an isolate with highest cellulase activity was chosen for the production, partial purification, and biochemical characterization of the enzyme. Different staining techniques, enzymatic tests, and 16s ribosomal DNA (16s rDNA) gene sequencing were used for the identification of the isolate. The cellulase producing isolate was Gram positive, motile, and sporulated rod-shaped bacterium growing optimally between 55°C and 65°C. Based on partial 16s rDNA sequence analysis, the isolate was identified as Geobacillus sp. and was designated as Geobacillus sp. KP43. The cellulase enzyme production condition was optimized, and the product was partially purified and biochemically characterized. Optimum cellulase production was observed in 1% carboxymethyl cellulose (CMC) at 55°C. The molecular weight of the enzyme was found to be approximately 66 kDa on 12% SDS-PAGE analysis. Biochemical characterization of partially purified enzyme revealed the temperature optimum of 70°C and activity over a wide pH range. Further, cellulase activity was markedly stimulated by metal ion Fe2+. Apart from cellulases, the isolate also depicted good xylanase, cellobiase, and amylase activities. Thermophilic growth with a variety of extracellular enzyme activities at elevated temperature as well as in a wide pH range showed that the isolated bacteria, Geobacillus sp. KP43, can withstand the harsh environmental condition, which makes this organism suitable for enzyme production for various biotechnological and industrial applications.
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Mustafa M, Ali L, Islam W, Noman A, Zhou C, Shen L, Zhu T, Can L, Nasif O, Gasparovic K, latif F, Gao J. Heterologous expression and characterization of glycoside hydrolase with its potential applications in hyperthermic environment. Saudi J Biol Sci 2022; 29:751-757. [PMID: 35197741 PMCID: PMC8847942 DOI: 10.1016/j.sjbs.2021.09.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/07/2021] [Accepted: 09/29/2021] [Indexed: 01/25/2023] Open
Abstract
With the progressive focus on renewable energy via biofuels production from lignocellulosic biomass, cellulases are the key enzymes that play a fundamental role in this regard. This study aims to unravel the characteristics of Thermotoga maritima MSB8 (Tma) (a hyperthermophile from hot springs) thermostable glycoside hydrolase enzyme. Here, a glycoside hydrolase gene of Thermotoga maritima (Tma) was heterologously expressed and characterized. The gene was placed in the pQE-30 expression vector under the T5 promotor, and the construct pQE-30-Gh was then successfully integrated into Escherichia coli BL21 (DH5α) genome by transformation. Sequence of the glycoside hydrolase contained an open reading frame of 2.124 kbp, encoded a polypeptide of 721 amino acid residues. The molecular weight of the recombinant protein estimated was 79 kDa. The glycoside hydrolase was purified by Ni+2-NTA affinity chromatography and its enzymatic activity was investigated. The recombinant enzyme is highly stable within an extreme pH range (2.0–7.0) and highly thermostable at 80 °C for 72 h indicating its viability in hyperthermic environment and acidic nature. Moreover, the Ca2+ and Mn2+ introduction stimulated the residual activity of recombinant enzyme. Conclusively, the thermostable glycoside hydrolase possesses potential to be exploited for industrial applications at hyperthermic environment.
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Affiliation(s)
- Muhammad Mustafa
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Liaqat Ali
- Kansas State University, Manhattan, KS 66506, United States
| | - Waqar Islam
- College of Geography, Fujian Normal University, Fuzhou 350007, China
| | - Ali Noman
- Department of Botany, Government College University, Faisalabad 38040, Pakistan
| | - Chengzeng Zhou
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Linsong Shen
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Taoting Zhu
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Liu Can
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Omaima Nasif
- Department of Physiology, College of Medicine and King Khalid University Hospital, King Saud University, Medical City, PO Box-2925, Riyadh 11461, Saudi Arabia
| | - Kristina Gasparovic
- Department of Plant Physiology, Slovak University of Agriculture, A.Hlinku 2, 94976, Slovakia
| | - Farooq latif
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Jiangtao Gao
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Corresponding author at: Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Bashir Z, Sheng L, Anil A, Lali A, Minton NP, Zhang Y. Engineering Geobacillus thermoglucosidasius for direct utilisation of holocellulose from wheat straw. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:199. [PMID: 31452680 PMCID: PMC6701081 DOI: 10.1186/s13068-019-1540-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 08/06/2019] [Indexed: 05/29/2023]
Abstract
BACKGROUND A consolidated bioprocessing (CBP), where lignocellulose is converted into the desired product(s) in a single fermentative step without the addition of expensive degradative enzymes, represents the ideal solution of renewable routes to chemicals and fuels. Members of the genus Geobacillus are able to grow at elevated temperatures and are able to utilise a wide range of oligosaccharides derived from lignocellulose. This makes them ideally suited to the development of CBP. RESULTS In this study, we engineered Geobacillus thermoglucosidasius NCIMB 11955 to utilise lignocellulosic biomass, in the form of nitric acid/ammonia treated wheat straw to which expensive hydrolytic enzymes had not been added. Two different strains, BZ9 and BZ10, were generated by integrating the cglT (β-1,4-glucosidase) gene from Thermoanaerobacter brockii into the genome, and localising genes encoding different cellulolytic enzymes on autonomous plasmids. The plasmid of strain BZ10 carried a synthetic cellulosomal operon comprising the celA (Endoglucanase A) gene from Clostridium thermocellum and cel6B (Exoglucanase) from Thermobifida fusca; whereas, strain BZ9 contained a plasmid encoding the celA (multidomain cellulase) gene from Caldicellulosiruptor bescii. All of the genes were successfully expressed, and their encoded products secreted in a functionally active form, as evidenced by their detection in culture supernatants by Western blotting and enzymatic assay. In the case of the C. bescii CelA enzyme, this is one of the first times that the heterologous production of this multi-functional enzyme has been achieved in a heterologous host. Both strains (BZ9 and BZ10) exhibited improved growth on pre-treated wheat straw, achieving a higher final OD600 and producing greater numbers of viable cells. To demonstrate that cellulosic ethanol can be produced directly from lignocellulosic biomass by a single organism, we established our consortium of hydrolytic enzymes in a previously engineered ethanologenic G. thermoglucosidasius strain, LS242. We observed approximately twofold and 1.6-fold increase in ethanol production in the recombinant G. thermoglucosidasius equivalent to BZ9 and BZ10, respectively, compared to G. thermoglucosidasius LS242 strain at 24 h of growth. CONCLUSION We engineered G. thermoglucosidasius to utilise a real-world lignocellulosic biomass substrate and demonstrated that cellulosic ethanol can be produced directly from lignocellulosic biomass in one step. Direct conversion of biomass into desired products represents a new paradigm for CBP, offering the potential for carbon neutral, cost-effective production of sustainable chemicals and fuels.
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Affiliation(s)
- Zeenat Bashir
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Lili Sheng
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Annamma Anil
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Nathalal Parikh Marg, Mumbai, 400019 India
| | - Arvind Lali
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Nathalal Parikh Marg, Mumbai, 400019 India
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Ying Zhang
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
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Han H, Ling Z, Khan A, Virk AK, Kulshrestha S, Li X. Improvements of thermophilic enzymes: From genetic modifications to applications. BIORESOURCE TECHNOLOGY 2019; 279:350-361. [PMID: 30755321 DOI: 10.1016/j.biortech.2019.01.087] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/19/2019] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
Thermozymes (from thermophiles or hyperthermophiles) offer obvious advantages due to their excellent thermostability, broad pH adaptation, and hydrolysis ability, resulting in diverse industrial applications including food, paper, and textile processing, biofuel production. However, natural thermozymes with low yield and poor adaptability severely hinder their large-scale applications. Extensive studies demonstrated that using genetic modifications such as directed evolution, semi-rational design, and rational design, expression regulations and chemical modifications effectively improved enzyme's yield, thermostability and catalytic efficiency. However, mechanism-based techniques for thermozymes improvements and applications need more attention. In this review, stabilizing mechanisms of thermozymes are summarized for thermozymes improvements, and these improved thermozymes eventually have large-scale industrial applications.
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Affiliation(s)
- Huawen Han
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, People's Republic of China
| | - Zhenmin Ling
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, People's Republic of China
| | - Aman Khan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, People's Republic of China
| | - Amanpreet Kaur Virk
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh 173229, India
| | - Saurabh Kulshrestha
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh 173229, India
| | - Xiangkai Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, People's Republic of China.
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Patel AK, Singhania RR, Sim SJ, Pandey A. Thermostable cellulases: Current status and perspectives. BIORESOURCE TECHNOLOGY 2019; 279:385-392. [PMID: 30685132 DOI: 10.1016/j.biortech.2019.01.049] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 05/18/2023]
Abstract
It is envisaged that the utilization of lignocellulosic biomass for ethanol production for transport sector, would make cellulases the most demanded industrial enzyme. The greatest potential of cellulolytic enzymes lies in ethanol production from biomass by enzymatic hydrolysis of cellulose but low thermostability and low titer of cellulase production resulting into high cost of the enzyme which is the major set-back. A number of research groups are working on cellulase to improve its thermostability so as to be able to perform hydrolysis at elevated temperatures which would eventually increase the efficiency of cellulose hydrolysis. The technologies developed from lignocellulosic biomass via cellulose hydrolysis promise environmental and economical sustainability in the long run along with non-dependence on nonrenewable energy source. This review deals with the important sources of thermostable cellulases, mechanism, its regulation, strategies to enhance the thermostability further with respect to its importance for biofuel applications.
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Affiliation(s)
- Anil K Patel
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | | | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Ashok Pandey
- Centre for Innovation and Translational Research, Indian Institute of Toxicological Research, Lucknow 226 001, India
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Jing K, Guo Y, Ng IS. Antigen-43-mediated surface display revealed in Escherichia coli by different fusion sites and proteins. BIORESOUR BIOPROCESS 2019. [DOI: 10.1186/s40643-019-0248-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Biochemical and functional characterization of a novel thermoacidophilic, heat and halo-ionic liquids tolerant endo-β-1,4-glucanase from saline-alkaline lake soil microbial metagenomic DNA. Int J Biol Macromol 2018; 118:1035-1044. [DOI: 10.1016/j.ijbiomac.2018.06.141] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 06/26/2018] [Accepted: 06/26/2018] [Indexed: 11/21/2022]
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Daas MJA, Nijsse B, van de Weijer AHP, Groenendaal BWAJ, Janssen F, van der Oost J, van Kranenburg R. Engineering Geobacillus thermodenitrificans to introduce cellulolytic activity; expression of native and heterologous cellulase genes. BMC Biotechnol 2018; 18:42. [PMID: 29945583 PMCID: PMC6020330 DOI: 10.1186/s12896-018-0453-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 06/14/2018] [Indexed: 11/28/2022] Open
Abstract
Background Consolidated bioprocessing (CBP) is a cost-effective approach for the conversion of lignocellulosic biomass to biofuels and biochemicals. The enzymatic conversion of cellulose to glucose requires the synergistic action of three types of enzymes: exoglucanases, endoglucanases and β-glucosidases. The thermophilic, hemicellulolytic Geobacillus thermodenitrificans T12 was shown to harbor desired features for CBP, although it lacks the desired endo and exoglucanases required for the conversion of cellulose. Here, we report the expression of both endoglucanase and exoglucanase encoding genes by G. thermodenitrificans T12, in an initial attempt to express cellulolytic enzymes that complement the enzymatic machinery of this strain. Results A metagenome screen was performed on 73 G. thermodenitrificans strains using HMM profiles of all known CAZy families that contain endo and/or exoglucanases. Two putative endoglucanases, GE39 and GE40, belonging to glucoside hydrolase family 5 (GH5) were isolated and expressed in both E. coli and G. thermodenitrificans T12. Structure modeling of GE39 revealed a folding similar to a GH5 exo-1,3-β-glucanase from S. cerevisiae. However, we determined GE39 to be a β-xylosidase having pronounced activity towards p-nitrophenyl-β-d-xylopyranoside. Structure modelling of GE40 revealed its protein architecture to be similar to a GH5 endoglucanase from B. halodurans, and its endoglucanase activity was confirmed by enzymatic activity against 2-hydroxyethylcellulose, carboxymethylcellulose and barley β-glucan. Additionally, we introduced expression constructs into T12 containing Geobacillus sp. 70PC53 endoglucanase gene celA and both endoglucanase genes (M1 and M2) from Geobacillus sp. WSUCF1. Finally, we introduced expression constructs into T12 containing the C. thermocellum exoglucanases celK and celS genes and the endoglucanase celC gene. Conclusions We identified a novel G. thermodenitrificans β-xylosidase (GE39) and a novel endoglucanase (GE40) using a metagenome screen based on multiple HMM profiles. We successfully expressed both genes in E. coli and functionally expressed the GE40 endoglucanase in G. thermodenitrificans T12. Additionally, the heterologous production of active CelK, a C. thermocellum derived exoglucanase, and CelA, a Geobacillus derived endoglucanase, was demonstrated with strain T12. The native hemicellulolytic activity and the heterologous cellulolytic activity described in this research provide a good basis for the further development of G. thermodenitrificans T12 as a host for consolidated bioprocessing. Electronic supplementary material The online version of this article (10.1186/s12896-018-0453-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martinus J A Daas
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Bart Nijsse
- Laboratory of Systems and Synthetic Biology, Wageningen University, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | | | - Bart W A J Groenendaal
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Fons Janssen
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - John van der Oost
- 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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Khan M, Sathya TA. Extremozymes from metagenome: Potential applications in food processing. Crit Rev Food Sci Nutr 2017; 58:2017-2025. [PMID: 28605203 DOI: 10.1080/10408398.2017.1296408] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The long-established use of enzymes for food processing and product formulation has resulted in an increased enzyme market compounding to 7.0% annual growth rate. Advancements in molecular biology and recognition that enzymes with specific properties have application for industrial production of infant, baby and functional foods boosted research toward sourcing the genes of microorganisms for enzymes with distinctive properties. In this regard, functional metagenomics for extremozymes has gained attention on the premise that such enzymes can catalyze specific reactions. Hence, metagenomics that can isolate functional genes of unculturable extremophilic microorganisms has expanded attention as a promising tool. Developments in this field of research in relation to food sector are reviewed.
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Affiliation(s)
- Mahejibin Khan
- a CSIR-Central Food Technological Research Institute-Resource Centre Lucknow , India.,c Academy of Scientific and Innovative Research , New Delhi , India
| | - T A Sathya
- b CSIR-Central Food Technological Research Institute , Mysore , India.,c Academy of Scientific and Innovative Research , New Delhi , India
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Azadian F, Badoei-dalfard A, Namaki-Shoushtari A, Karami Z, Hassanshahian M. Production and characterization of an acido-thermophilic, organic solvent stable cellulase from Bacillus sonorensis HSC7 by conversion of lignocellulosic wastes. J Genet Eng Biotechnol 2017; 15:187-196. [PMID: 30647655 PMCID: PMC6296611 DOI: 10.1016/j.jgeb.2016.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 11/15/2016] [Accepted: 12/19/2016] [Indexed: 01/06/2023]
Abstract
The acidophilic and thermophilic cellulase would facilitate the conversion of lignocellulosic biomass to biofuel. In this study, Bacillus sonorensis HSC7 isolated as the best thermophilic cellulose degrading bacterium from Gorooh hot spring. 16S rRNA gene sequencing showed that, this strain closely related to the B. sonorensis. CMCase production was considered under varying environmental parameters. Results showed that, sucrose and (NH4)2SO4 were obtained as the best carbon and nitrogen sources for CMCase production. B. sonorensis HSC7 produced CMCase during the growth in optimized medium supplemented with agricultural wastes as sole carbon sources. The enzyme was active with optimum temperature of 70 °C and the optimum CMCase activity and stability observed at pH 4.0 and 5.0, respectively. These are characteristics indicating that, this enzyme could be an acidophilic and thermophilic CMCase. Furthermore, the CMCase activity improved by methanol (166%), chloroform (152%), while it was inhibited by DMF (61%). The CMCase activity was enhanced in the presence of Mg+2 (110%), Cu+2 (116%), Triton X-100 (118%) and it retained 57% of its activity at 30% NaCl. The compatibility of HSC7 CMCase varied for each laundry detergent, with higher stability being observed in the presence of Taj® and darya®. This enzyme, that is able to work under extreme conditions, has potential applications in various industries.
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Affiliation(s)
| | - Arastoo Badoei-dalfard
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
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13
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Characterization of a thermophilic cellulase from Geobacillus sp. HTA426, an efficient cellulase-producer on alkali pretreated of lignocellulosic biomass. PLoS One 2017; 12:e0175004. [PMID: 28406925 PMCID: PMC5390992 DOI: 10.1371/journal.pone.0175004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 03/17/2017] [Indexed: 11/19/2022] Open
Abstract
A themophilic cellulase-producing bacterium was isolated from a hot spring district and identified as Geobacillus sp. HTA426. The cellulase enzyme produced by the Geobacillus sp. HTA426 was purified through ammonium sulfate precipitation and ion exchange chromatography, with the recovery yield and fold purification of 10.14% and 5.12, respectively. The purified cellulase has a molecular weight of 40 kDa. The optimum temperature and pH for carboxymethyl cellulase (CMCase) activity of the purified cellulase were 60°C and pH 7.0, respectively. The enzyme was also stable over a wide temperature range of 50°C to 70°C after 5 h of incubation. Moreover, the strain HTA426 was able to grow and produce cellulase on alkali-treated sugarcane bagasse, rice straw and water hyacinth as carbon sources. Enzymatic hydrolysis of sugarcane bagasse, which was regarded as the most effective carbon source for cellulase production (CMCase activity = 103.67 U/mL), followed by rice straw (74.70 U/mL) and water hyacinth (51.10 U/mL). This strain producing an efficient thermostable cellulose is a potential candidate for developing a more efficient and cost-effective process for converting lignocellulosic biomass into biofuel and other industrial process.
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14
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A novel pH-stable, endoglucanase (JqCel5A) isolated from a salt-lake microorganism, Jonesia quinghaiensis. ELECTRON J BIOTECHN 2016. [DOI: 10.1016/j.ejbt.2016.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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15
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Galanopoulou AP, Moraïs S, Georgoulis A, Morag E, Bayer EA, Hatzinikolaou DG. Insights into the functionality and stability of designer cellulosomes at elevated temperatures. Appl Microbiol Biotechnol 2016; 100:8731-43. [PMID: 27207145 DOI: 10.1007/s00253-016-7594-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/23/2016] [Accepted: 04/28/2016] [Indexed: 01/21/2023]
Abstract
Enzymatic breakdown of lignocellulose is a major limiting step in second generation biorefineries. Assembly of the necessary activities into designer cellulosomes increases the productivity of this step by enhancing enzyme synergy through the proximity effect. However, most cellulosomal components are obtained from mesophilic microorganisms, limiting the applications to temperatures up to 50 °C. We hypothesized that a scaffoldin, comprising modular components of mainly mesophilic origin, can function at higher temperatures when combined with thermophilic enzymes, and the resulting designer cellulosomes could be employed in higher temperature reactions. For this purpose, we used a tetravalent scaffoldin constituted of three cohesins of mesophilic origin as well as a cohesin and cellulose-binding module derived from the thermophilic bacterium Clostridium thermocellum. The scaffoldin was combined with four thermophilic enzymes from Geobacillus and Caldicellulosiruptor species, each fused with a dockerin whose specificity matched one of the cohesins. We initially verified that the biochemical properties and thermal stability of the resulting chimeric enzymes were not affected by the presence of the mesophilic dockerins. Then we examined the stability of the individual single-enzyme-scaffoldin complexes and the full tetravalent cellulosome showing that all complexes are stable and functional for at least 6 h at 60 °C. Finally, within this time frame and conditions, the full complex appeared over 50 % more efficient in the hydrolysis of corn stover compared to the free enzymes. Overall, the results support the utilization of scaffoldin components of mesophilic origin at relatively high temperatures and provide a framework for the production of designer cellulosomes suitable for high temperature biorefinery applications.
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Affiliation(s)
- Anastasia P Galanopoulou
- Faculty of Biology, Microbiology Group, National and Kapodistrian University of Athens, Zografou Campus, 15784, Zografou, Attica, Greece
| | - Sarah Moraïs
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Anastasios Georgoulis
- Faculty of Biology, Microbiology Group, National and Kapodistrian University of Athens, Zografou Campus, 15784, Zografou, Attica, Greece
| | - Ely Morag
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Dimitris G Hatzinikolaou
- Faculty of Biology, Microbiology Group, National and Kapodistrian University of Athens, Zografou Campus, 15784, Zografou, Attica, Greece.
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16
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Dong M, Yang Y, Tang X, Shen J, Xu B, Li J, Wu Q, Zhou J, Ding J, Han N, Mu Y, Huang Z. NaCl-, protease-tolerant and cold-active endoglucanase from Paenibacillus sp. YD236 isolated from the feces of Bos frontalis. SPRINGERPLUS 2016; 5:746. [PMID: 27376014 PMCID: PMC4909688 DOI: 10.1186/s40064-016-2360-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/17/2016] [Indexed: 12/20/2022]
Abstract
Bos frontalis, which consumes
bamboo and weeds, may have evolved unique gastrointestinal microorganisms that digest cellulase. A Paenibacillus sp. YD236 strain was isolated from B. frontalis feces, from which a GH8 endoglucanase gene, pglue8 (1107 bp, 54.5 % GC content), encoding a 368-residue polypeptide (PgluE8, 40.4 kDa) was cloned. PgluE8 efficiently hydrolyzed barley-β-d-glucan followed by CMC-Na, soluble starch, laminarin, and glucan from black yeast optimally at pH 5.5 and 50 °C, and retained 78.6, 41.6, and 34.5 % maximum activity when assayed at 20, 10, and 0 °C, respectively. Enzyme activity remained above 176.6 % after treatment with 10.0 mM β-mercaptoethanol, and was 83.0, 78, and 56 % after pre-incubation in 30 % (w/v) NaCl, 16.67 mg/mL trypsin, and 160.0 mg/mL protease K, respectively. Cys23 and Cys364 residues were critical for PgluE8 activity. pglue8, identified from B. frontalis feces for the first time in this study, is a potential alternative for applications including food processing, washing, and animal feed preparation.
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Affiliation(s)
- Mingjie Dong
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Yunjuan Yang
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Xianghua Tang
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Jidong Shen
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Bo Xu
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Junjun Li
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Qian Wu
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Junpei Zhou
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Junmei Ding
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Nanyu Han
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Yuelin Mu
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
| | - Zunxi Huang
- School of Life Science, Yunnan Normal University, Kunming, 650500 People's Republic of China.,Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, No.1 Yuhua District, Chenggong, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming, 650500 Yunnan People's Republic of China.,Key Laboratory of Enzyme Engineering, Yunnan Normal University, Kunming, 650500 People's Republic of China
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17
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Irfan M, Guler HI, Belduz AO, Shah AA, Canakci S. Cloning, purification and characterization of a cellulase-free xylanase from Geobacillus thermodenitrificans AK53. APPL BIOCHEM MICRO+ 2016. [DOI: 10.1134/s0003683816030066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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Chang CJ, Lee CC, Chan YT, Trudeau DL, Wu MH, Tsai CH, Yu SM, Ho THD, Wang AHJ, Hsiao CD, Arnold FH, Chao YC. Exploring the Mechanism Responsible for Cellulase Thermostability by Structure-Guided Recombination. PLoS One 2016; 11:e0147485. [PMID: 26986867 PMCID: PMC4795783 DOI: 10.1371/journal.pone.0147485] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/05/2016] [Indexed: 12/29/2022] Open
Abstract
Cellulases from Bacillus and Geobacillus bacteria are potentially useful in the biofuel and animal feed industries. One of the unique characteristics of these enzymes is that they are usually quite thermostable. We previously identified a cellulase, GsCelA, from thermophilic Geobacillus sp. 70PC53, which is much more thermostable than its Bacillus homolog, BsCel5A. Thus, these two cellulases provide a pair of structures ideal for investigating the mechanism regarding how these cellulases can retain activity at high temperature. In the present study, we applied the SCHEMA non-contiguous recombination algorithm as a novel tool, which assigns protein sequences into blocks for domain swapping in a way that lessens structural disruption, to generate a set of chimeric proteins derived from the recombination of GsCelA and BsCel5A. Analyzing the activity and thermostability of this designed library set, which requires only a limited number of chimeras by SCHEMA calculations, revealed that one of the blocks may contribute to the higher thermostability of GsCelA. When tested against swollen Avicel, the highly thermostable chimeric cellulase C10 containing this block showed significantly higher activity (22%-43%) and higher thermostability compared to the parental enzymes. With further structural determinations and mutagenesis analyses, a 310 helix was identified as being responsible for the improved thermostability of this block. Furthermore, in the presence of ionic calcium and crown ether (CR), the chimeric C10 was found to retain 40% residual activity even after heat treatment at 90°C. Combining crystal structure determinations and structure-guided SCHEMA recombination, we have determined the mechanism responsible for the high thermostability of GsCelA, and generated a novel recombinant enzyme with significantly higher activity.
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Affiliation(s)
- Chia-Jung Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Cheng-Chung Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, ROC
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan, ROC
| | - Yueh-Te Chan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, ROC
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan, ROC
| | - Devin L. Trudeau
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Mei-Huey Wu
- Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, ROC
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Chih-Hsuan Tsai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Tuan-Hua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Andrew H.-J. Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, ROC
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan, ROC
| | - Chwan-Deng Hsiao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Yu-Chan Chao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
- * E-mail:
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19
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Castiglia D, Sannino L, Marcolongo L, Ionata E, Tamburino R, De Stradis A, Cobucci-Ponzano B, Moracci M, La Cara F, Scotti N. High-level expression of thermostable cellulolytic enzymes in tobacco transplastomic plants and their use in hydrolysis of an industrially pretreated Arundo donax L. biomass. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:154. [PMID: 27453729 PMCID: PMC4957871 DOI: 10.1186/s13068-016-0569-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/12/2016] [Indexed: 05/06/2023]
Abstract
BACKGROUND Biofuels production from plant biomasses is a complex multi-step process with important economic burdens. Several biotechnological approaches have been pursued to reduce biofuels production costs. The aim of the present study was to explore the production in tobacco plastome of three genes encoding (hemi)cellulolytic enzymes from thermophilic and hyperthermophilic bacterium and Archaea, respectively, and test their application in the bioconversion of an important industrially pretreated biomass feedstock (A. donax) for production of second-generation biofuels. RESULTS The selected enzymes, endoglucanase, endo-β-1,4-xylanase and β-glucosidase, were expressed in tobacco plastome with a protein yield range from 2 % to more than 75 % of total soluble proteins (TSP). The accumulation of endoglucanase (up to 2 % TSP) gave altered plant phenotypes whose severity was directly linked to the enzyme yield. The most severe seedling-lethal phenotype was due to the impairment of plastid development associated to the binding of endoglucanase protein to thylakoids. Endo-β-1,4-xylanase and β-glucosidase, produced at very high level without detrimental effects on plant development, were enriched (fourfold) by heat treatment (105.4 and 255.4 U/mg, respectively). Both plastid-derived biocatalysts retained the main features of the native or recombinantly expressed enzymes with interesting differences. Plastid-derived xylanase and β-glucosidase resulted more thermophilic than the E. coli recombinant and native counterpart, respectively. Bioconversion experiments, carried out at 50 and 60 °C, demonstrated that plastid-derived enzymes were able to hydrolyse an industrially pretreated giant reed biomass. In particular, the replacement of commercial enzyme with plastid-derived xylanase, at 60 °C, produced an increase of both xylose recovery and hydrolysis rate; whereas the replacement of both xylanase and β-glucosidase produced glucose levels similar to those observed with the commercial cocktails, and xylose yields always higher in the whole 24-72 h range. CONCLUSIONS The very high production level of thermophilic and hyperthermophilic enzymes, their stability and bioconversion efficiencies described in this study demonstrate that plastid transformation represents a real cost-effective production platform for cellulolytic enzymes.
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Affiliation(s)
- Daniela Castiglia
- />CNR-IBBR UOS Portici, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Via Università 133, 80055 Portici, NA Italy
| | - Lorenza Sannino
- />CNR-IBBR UOS Portici, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Via Università 133, 80055 Portici, NA Italy
| | - Loredana Marcolongo
- />CNR-IBBR UOS Naples, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Naples, Via P. Castellino 111, Naples, Italy
- />CNR-IBAF UOS Napoli, National Research Council of Italy, Institute of Agro-environmental and Forest Biology, Research Division Naples, Via P. Castellino 111, Naples, Italy
| | - Elena Ionata
- />CNR-IBBR UOS Naples, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Naples, Via P. Castellino 111, Naples, Italy
- />CNR-IBAF UOS Napoli, National Research Council of Italy, Institute of Agro-environmental and Forest Biology, Research Division Naples, Via P. Castellino 111, Naples, Italy
| | - Rachele Tamburino
- />CNR-IBBR UOS Portici, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Via Università 133, 80055 Portici, NA Italy
| | - Angelo De Stradis
- />CNR-IPSP UOS Bari, National Research Council of Italy, Institute for Sustainable Plant Protection, Research Division Bari, Via Amendola 165/A, 70126 Bari, Italy
| | - Beatrice Cobucci-Ponzano
- />CNR-IBBR UOS Naples, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Naples, Via P. Castellino 111, Naples, Italy
| | - Marco Moracci
- />CNR-IBBR UOS Naples, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Naples, Via P. Castellino 111, Naples, Italy
| | - Francesco La Cara
- />CNR-IBBR UOS Naples, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Naples, Via P. Castellino 111, Naples, Italy
- />CNR-IBAF UOS Napoli, National Research Council of Italy, Institute of Agro-environmental and Forest Biology, Research Division Naples, Via P. Castellino 111, Naples, Italy
| | - Nunzia Scotti
- />CNR-IBBR UOS Portici, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Via Università 133, 80055 Portici, NA Italy
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20
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Daas MJA, van de Weijer AHP, de Vos WM, van der Oost J, van Kranenburg R. Isolation of a genetically accessible thermophilic xylan degrading bacterium from compost. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:210. [PMID: 27752284 PMCID: PMC5053077 DOI: 10.1186/s13068-016-0618-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/20/2016] [Indexed: 05/20/2023]
Abstract
BACKGROUND Due to the finite nature of global oil resources we are now faced with the challenge of finding renewable resources to produce fuels and chemicals in the future. Lactic acid has great potential as a precursor for the production of bioplastics alternatives to conventional plastics. Efficient lactic acid fermentation from non-food lignocellulosic substrates requires pretreatment and saccharification to generate fermentable sugars. A fermentation process that requires little to no enzyme additions, i.e. consolidated bioprocessing would be preferred and requires lactic acid-producing organisms that have cellulolytic and/or hemicellulolytic activity. RESULTS To obtain candidate production strains we have enriched and isolated facultative anaerobic (hemi) cellulolytic bacterial strains from compost samples. By selecting for growth on both cellulose and xylan, 94 Geobacillus strains were isolated. Subsequent screening for lactic acid production was carried out from C6 and C5 sugar fermentations and a selection of the best lactic acid producers was made. The denitrifying Geobacillus thermodenitrificans T12 was selected for further research and was rendered genetically accessible. In fermentations on a mixture of glucose and xylose, a total of 20.3 g of lactic acid was produced with a yield of 0.94 g product/g sugar consumed. In addition, strain T12 is capable of direct conversion of beech wood xylan to mainly lactic acid in minimal media. CONCLUSIONS We have demonstrated that G. thermodenitrificans T12 is genetically accessible and produces lactic acid as its main fermentation product on glucose, xylose and a mixture thereof. Strain T12 was additionally used for the direct conversion of xylan to lactic acid. The genetic accessibility of the T12 strain provides a solid basis for the development of this strain into a host for consolidated bioprocessing of biomass to lactic acid.
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Affiliation(s)
- Martinus J. A. Daas
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | | | - Willem M. de Vos
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - John van der Oost
- 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, Arkselsedijk 46, 4206 AC Gorinchem, The Netherlands
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21
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Pandey S, Gulati S, Goyal E, Singh S, Kumar K, Nain L, Saxena A. Construction and screening of metagenomic library derived from soil for β-1, 4-endoglucanase gene. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2016. [DOI: 10.1016/j.bcab.2016.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Khare SK, Pandey A, Larroche C. Current perspectives in enzymatic saccharification of lignocellulosic biomass. Biochem Eng J 2015. [DOI: 10.1016/j.bej.2015.02.033] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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23
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Yeasmin S, Kim CH, Islam SMA, Lee JY. Population dynamics of cellulolytic bacteria depend on the richness of cellulosic materials in the habitat. Microbiology (Reading) 2015. [DOI: 10.1134/s0026261715020186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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24
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Sathya T, Khan M. Diversity of Glycosyl Hydrolase Enzymes from Metagenome and Their Application in Food Industry. J Food Sci 2014; 79:R2149-56. [DOI: 10.1111/1750-3841.12677] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 08/18/2014] [Indexed: 11/29/2022]
Affiliation(s)
- T.A. Sathya
- Academy of Scientific and Innovative Research; New Delhi India
- CSIR-Central Food Technological Research Institute; Mysore-20 Karnataka India
| | - Mahejibin Khan
- Academy of Scientific and Innovative Research; New Delhi India
- CSIR-Central Food Technological Research Institute; Mysore-20 Karnataka India
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25
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Iqbal I, Aftab MN, Afzal M, Ur-Rehman A, Aftab S, Zafar A, Ud-Din Z, Khuharo AR, Iqbal J, Ul-Haq I. Purification and characterization of cloned alkaline protease gene ofGeobacillus stearothermophilus. J Basic Microbiol 2014; 55:160-71. [DOI: 10.1002/jobm.201400190] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 08/05/2014] [Indexed: 12/27/2022]
Affiliation(s)
- Irfana Iqbal
- Institute of Industrial Biotechnology; GC University; Lahore Pakistan
| | | | - Mohammed Afzal
- Department of Biological Sciences; Kuwait University; Kuwait
| | - Asad Ur-Rehman
- Institute of Industrial Biotechnology; GC University; Lahore Pakistan
| | - Saima Aftab
- Institute of Industrial Biotechnology; GC University; Lahore Pakistan
| | - Asma Zafar
- Institute of Industrial Biotechnology; GC University; Lahore Pakistan
| | - Zia Ud-Din
- Institute of Industrial Biotechnology; GC University; Lahore Pakistan
| | | | - Jawad Iqbal
- Department of Microbiology; Quaid-e-Azam University; Islamabad Pakistan
| | - Ikram Ul-Haq
- Institute of Industrial Biotechnology; GC University; Lahore Pakistan
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Meng F, Ma L, Ji S, Yang W, Cao B. Isolation and characterization of Bacillus subtilis strain BY-3, a thermophilic and efficient cellulase-producing bacterium on untreated plant biomass. Lett Appl Microbiol 2014; 59:306-12. [PMID: 24773580 DOI: 10.1111/lam.12276] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 03/24/2014] [Accepted: 04/15/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED Bioconversion of biomass, particularly crop wastes, into biofuels is being developed as an alternative approach in meeting the high energy demand. In this study, a thermophilic bacterial strain BY-3 that exhibits cellulolytic potential was isolated from faecal samples of Tibetan pigs; this strain was identified as Bacillus subtilis. The strain can produce cellulase when grown on various substrates, including carboxymethyl cellulose, rice straw, corn stover, soluble starch and wheat bran. The maximum cellulase activity of the strain was up to 4·323 ± 0·065 U ml(-1) when cultivated in the medium containing corn stover (30 g l(-1) ) for 24 h. The results demonstrated that corn stover is the most suitable substrate for cellulase production by the strain BY-3. The crude cellulase of strain BY-3 was most active at pH 5·5 and 60°C, and the enzyme in acetate buffer (50 mmol l(-1) ) demonstrated a good stability at 60°C for at least 1 h. The crude cellulase exhibited a strong antibacterial activity against Staphylococcus aureus. The strain can be used in cost-efficient cellulase production for bioconversion of agricultural residual biomass into biofuels. SIGNIFICANCE AND IMPACT OF THE STUDY The increased consumption of fossil fuels has caused serious energy crisis and environmental problem. Thus, an alternative energy source is necessary. Bioconversion of biomass, particularly agricultural residuals, into value-added bioproducts, such as biofuels and chemical solvents, has received considerable attention. In this study, the newly isolated thermophilic Bacillus subtilis strain BY-3 produces cellulase efficiently with the use of untreated corn stover as a sole carbon source. This strain possesses the thermostable cellulase that is active with diverse crop wastes with a broad pH range and is a highly promising candidate for agricultural waste management.
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Affiliation(s)
- F Meng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
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Blumer-Schuette SE, Brown SD, Sander KB, Bayer EA, Kataeva I, Zurawski JV, Conway JM, Adams MWW, Kelly RM. Thermophilic lignocellulose deconstruction. FEMS Microbiol Rev 2014; 38:393-448. [DOI: 10.1111/1574-6976.12044] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 08/20/2013] [Accepted: 08/28/2013] [Indexed: 11/28/2022] Open
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Recombinant expression and characterization of a novel endoglucanase from Bacillus subtilis in Escherichia coli. Mol Biol Rep 2014; 41:3295-302. [PMID: 24493451 DOI: 10.1007/s11033-014-3192-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 01/22/2014] [Indexed: 10/25/2022]
Abstract
The goal of this work was to produce high levels of endoglucanase in Escherichia coli for its potential usage in different industrial applications. Endoglucanase gene was amplified from genomic DNA of Bacillus subtilis JS2004 by PCR. The isolated putative endoglucanase gene consisted of an open reading frame of 1,701 nucleotides and encoded a protein of 567 amino acids with a molecular mass of 63-kDa. The gene was cloned into pET-28a(+) and expressed in E. coli BL21 (DE3). Optimum temperature and pH of the recombinant endoglucanase were 50 °C and 9, respectively which makes it very attractive for using in bio-bleaching and pulp industry. It had a K M of 1.76 μmol and V max 0.20 μmol/min with carboxymethylcellulose as substrate. The activity of recombinant endoglucanse was enhanced by Mg2+, Ca2+, isopropanol and Tween 20 and inhibited by Hg2+, Zn2+, Cu2+, Ni2+ and SDS. The activity of this recombinant endoglucanase was significantly higher than wild type. Therefore, this recombinant enzyme has potential for many industrial applications involving biomass conversions, due to characteristic of broad pH and higher temperature stability.
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Characterization of a native cellulase activity from an anaerobic thermophilic hydrogen-producing bacterium Thermosipho sp. strain 3. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-013-0792-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Ng IS, Chi X, Wu X, Bao Z, Lu Y, Chang JS, Ling X. Cloning and expression of Cel8A from Klebsiella pneumoniae in Escherichia coli and comparison to cel gene of Cellulomonas uda. Biochem Eng J 2013. [DOI: 10.1016/j.bej.2013.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Sakatoku A, Tanaka D, Kamachi H, Nakamura S. Cloning and Characterizing the Thermophilic and Detergent Stable Cellulase CelMytB from Saccharophagus sp. Myt-1. Indian J Microbiol 2013; 54:20-6. [PMID: 24426162 DOI: 10.1007/s12088-013-0421-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022] Open
Abstract
We previously isolated and reported a second species of the Saccharophagus genus, Saccharophagus sp. strain Myt-1. In the present study, a cellulase gene (celMytB) from the genomic DNA of Myt-1 was cloned and characterized. The DNA sequence fragment contained an open reading frame of 1,893 bp that encoded a protein of 631 amino acids with an estimated molecular mass of 66.8 kDa. The deduced protein, CelMytB, had a catalytic domain that contained a conserved signature sequence (VIYEIYNEPL) of glycosyl hydrolase family 5 and a CBM6 cellulose binding module. CelMytB showed optimal activity at 55 °C and pH 6.5, which is similar to the optimal temperature and pH profile of cel5H, an endoglucanase from the closely related S. degradans 2-40. However, the cellulase (degradation of soluble cellulose) and avicelase (degradation of crystalline cellulose) activities of CelMytB were about 3-fold and 100-fold higher, respectively, than the equivalent activities of cel5H. Moreover, CelMytB could degrade xylan. From the zymogram results, we speculated that the catalytic domain of CelMytB had high activity even without the cellulose binding module. The presence of some detergents stimulated the cellulase activity of CelMytB.
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Affiliation(s)
- Akihiro Sakatoku
- Department of Environmental and Energy Science, Faculty of Earth and Environmental Systems, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan
| | - Daisuke Tanaka
- Department of Environmental and Energy Science, Faculty of Earth and Environmental Systems, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan
| | - Hiroyuki Kamachi
- Department of Environmental and Energy Science, Faculty of Earth and Environmental Systems, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan
| | - Shogo Nakamura
- Department of Environmental and Energy Science, Faculty of Earth and Environmental Systems, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan
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Yeh YF, Chang SCY, Kuo HW, Tong CG, Yu SM, Ho THD. A metagenomic approach for the identification and cloning of an endoglucanase from rice straw compost. Gene 2013; 519:360-6. [DOI: 10.1016/j.gene.2012.07.076] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 07/14/2012] [Accepted: 07/31/2012] [Indexed: 10/28/2022]
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33
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Thermostable and Alkalistable Endoxylanase of the Extremely Thermophilic Bacterium Geobacillus thermodenitrificans TSAA1: Cloning, Expression, Characteristics and Its Applicability in Generating Xylooligosaccharides and Fermentable Sugars. Appl Biochem Biotechnol 2013; 170:119-30. [DOI: 10.1007/s12010-013-0174-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 03/01/2013] [Indexed: 10/27/2022]
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Cloning, expression and characteristics of a novel alkalistable and thermostable xylanase encoding gene (Mxyl) retrieved from compost-soil metagenome. PLoS One 2013; 8:e52459. [PMID: 23382818 PMCID: PMC3561394 DOI: 10.1371/journal.pone.0052459] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 11/19/2012] [Indexed: 11/19/2022] Open
Abstract
Background The alkalistable and thermostable xylanases are in high demand for pulp bleaching in paper industry and generating xylooligosaccharides by hydrolyzing xylan component of agro-residues. The compost-soil samples, one of the hot environments, are expected to be a rich source of microbes with thermostable enzymes. Methodology/Principal Findings Metagenomic DNA from hot environmental samples could be a rich source of novel biocatalysts. While screening metagenomic library constructed from DNA extracted from the compost-soil in the p18GFP vector, a clone (TSDV-MX1) was detected that exhibited clear zone of xylan hydrolysis on RBB xylan plate. The sequencing of 6.321 kb DNA insert and its BLAST analysis detected the presence of xylanase gene that comprised 1077 bp. The deduced protein sequence (358 amino acids) displayed homology with glycosyl hydrolase (GH) family 11 xylanases. The gene was subcloned into pET28a vector and expressed in E. coli BL21 (DE3). The recombinant xylanase (rMxyl) exhibited activity over a broad range of pH and temperature with optima at pH 9.0 and 80°C. The recombinant xylanase is highly thermostable having T1/2 of 2 h at 80°C and 15 min at 90°C. Conclusion/Significance This is the first report on the retrieval of xylanase gene through metagenomic approach that encodes an enzyme with alkalistability and thermostability. The recombinant xylanase has a potential application in paper and pulp industry in pulp bleaching and generating xylooligosaccharides from the abundantly available agro-residues.
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Pandey S, Singh S, Yadav AN, Nain L, Saxena AK. Phylogenetic diversity and characterization of novel and efficient cellulase producing bacterial isolates from various extreme environments. Biosci Biotechnol Biochem 2013; 77:1474-80. [PMID: 23832366 DOI: 10.1271/bbb.130121] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A set of 300 bacterial strains isolated from various extreme environments were screened for the presence of cellulase activity on CMC agar plates. Phylogenetic analysis of the positive strain, based on 16S rRNA gene sequences indicated that the isolates were clustered within Firmicutes and Actinobacteria. A majority (17) of the isolates were identified as Bacillus, Paenibacillus, and Lysinibacillus sp., and the remaining three were identified as Arthobacter, Rhodococcus, and Bhargavaea cecembensis. Among the 20 positive isolates, 6 were evaluated for the production of cellulases on five different cellulosic substrates. Two isolates, B. cecembensis and Bacillus sp., based on maximum enzyme production on all cellulosic substrates, especially CMC and rice straw, were evaluated in terms of enzyme properties and kinetics. The enzymes of these two isolates are found to be active over broad range of pH and temperature. Such thermostable enzymes facilitate the development of efficient and cost-effective forms of the simultaneous saccharification and fermentation process converting lignocellulosic biomass into biofuels and value-added products.
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Affiliation(s)
- Sangeeta Pandey
- Division of Microbiology, Indian Agricultural Research Institute, New Delhi 110012, India
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Bhalla A, Bansal N, Kumar S, Bischoff KM, Sani RK. Improved lignocellulose conversion to biofuels with thermophilic bacteria and thermostable enzymes. BIORESOURCE TECHNOLOGY 2013; 128:751-9. [PMID: 23246299 DOI: 10.1016/j.biortech.2012.10.145] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 09/20/2012] [Accepted: 10/29/2012] [Indexed: 05/07/2023]
Abstract
Second-generation feedstock, especially nonfood lignocellulosic biomass is a potential source for biofuel production. Cost-intensive physical, chemical, biological pretreatment operations and slow enzymatic hydrolysis make the overall process of lignocellulosic conversion into biofuels less economical than available fossil fuels. Lignocellulose conversions carried out at ≤ 50 °C have several limitations. Therefore, this review focuses on the importance of thermophilic bacteria and thermostable enzymes to overcome the limitations of existing lignocellulosic biomass conversion processes. The influence of high temperatures on various existing lignocellulose conversion processes and those that are under development, including separate hydrolysis and fermentation, simultaneous saccharification and fermentation, and extremophilic consolidated bioprocess are also discussed.
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Affiliation(s)
- Aditya Bhalla
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
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37
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Assareh R, Shahbani Zahiri H, Akbari Noghabi K, Aminzadeh S, Bakhshi Khaniki G. Characterization of the newly isolated Geobacillus sp. T1, the efficient cellulase-producer on untreated barley and wheat straws. BIORESOURCE TECHNOLOGY 2012; 120:99-105. [PMID: 22784959 DOI: 10.1016/j.biortech.2012.06.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 06/10/2012] [Accepted: 06/11/2012] [Indexed: 06/01/2023]
Abstract
A thermophile cellulase-producing bacterium was isolated and identified as closely related to Geobacillus subterraneus. The strain, named Geobacillus sp. T1, was able to grow and produce cellulase on cellobiose, microcrystalline cellulose, carboxymethylcellulose (CMC), barley straw, wheat straw and Whatman No. 1 filter paper. However, barley and wheat straws were significantly better substrates for cellulase production. When Geobacillus sp. T1 was cultivated in the presence of 0.5% barley straw, 0.1% Tween 80 and pH 6.5 at 50°C, the maximum level of free cellulase up to 143.50 U/mL was produced after 24h. This cellulase (≈ 54 kDa) was most active at pH 6.5 and 70°C. The enzyme in citrate phosphate buffer (10mM) was stable at 60°C for at least 1h. Geobacillus sp. T1 with efficient growth and cellulase production on straws seems a potential candidate for conversion of agricultural biomass to fuels.
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Affiliation(s)
- Reza Assareh
- Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran 14155-6343, Iran
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38
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Gerasimova J, Kuisiene N. Characterization of the novel xylanase from the thermophilic Geobacillus thermodenitrificans JK1. Microbiology (Reading) 2012. [DOI: 10.1134/s0026261712040066] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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39
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Assessment of the biomass hydrolysis potential in bacterial isolates from a volcanic environment: biosynthesis of the corresponding activities. World J Microbiol Biotechnol 2012; 28:2889-902. [DOI: 10.1007/s11274-012-1100-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 06/05/2012] [Indexed: 11/25/2022]
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40
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Verma D, Satyanarayana T. Cloning, expression and applicability of thermo-alkali-stable xylanase of Geobacillus thermoleovorans in generating xylooligosaccharides from agro-residues. BIORESOURCE TECHNOLOGY 2012; 107:333-338. [PMID: 22212694 DOI: 10.1016/j.biortech.2011.12.055] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 12/11/2011] [Accepted: 12/12/2011] [Indexed: 05/31/2023]
Abstract
A xylanase gene (xyl-gt) of 1.224 kbp was cloned from the extremely thermophilic bacterium Geobacillus thermoleovorans that encodes a protein containing 408 amino acid residues. Eight conserved regions (signature sequences) of GH family 10 xylanases have been found in the xylanase. When the xylanase gene was cloned and expressed in Escherichia coli BL21 (DE3), the recombinant strain produced xylanase titer of 270 U mg(-1) which is 27-fold higher than the wild strain. It is optimally active at 80°C and pH 8.5 with a high thermostability over broad range of pH (6-12) and temperature (40-100°C). The end products of the hydrolysis of birch wood xylan and agro-residues included xylobiose, xylotriose, xylotetraose and xylopentaose. The xylanase of G. thermoleovorans is one of the rare xylanases that exhibits thermo-alkali-stability, and thus, it is a suitable candidate for pre-bleaching of paper pulps and generating xylooligosaccharides from agro-residues for use as prebiotics.
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Affiliation(s)
- Digvijay Verma
- Department of Microbiology, University of Delhi South Campus, New Delhi 110 021, India
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41
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Liang C, Fioroni M, Rodríguez-Ropero F, Xue Y, Schwaneberg U, Ma Y. Directed evolution of a thermophilic endoglucanase (Cel5A) into highly active Cel5A variants with an expanded temperature profile. J Biotechnol 2011; 154:46-53. [PMID: 21501637 DOI: 10.1016/j.jbiotec.2011.03.025] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 03/03/2011] [Accepted: 03/29/2011] [Indexed: 10/18/2022]
Abstract
Cel5A is a highly active endoglucanase from Thermoanaerobacter tengcongensis MB4, displaying an optimal temperature range between 75 and 80°C. After three rounds of error-prone PCR and screening of 4700 mutants, five variants of Cel5A with improved activities were identified by Congo Red based screening method. Compared with the wild type, the best variants 3F6 and C3-13 display 135±6% and 193±8% of the wild type specific activity for the substrate carboxymethyl cellulose (CMC), besides improvements in the relative expression level in Escherichia coli system. Remarkable are especially the improvements in activities at reduced temperatures (50% of maximum activity at 50°C and about 45°C respectively, while 65°C for the wild type). Molecular Dynamics simulations performed on the 3F6 and C3-13 variants show a decreased number of intra-Cel5A hydrogen bonds compared to the wild type, implying a more flexible protein skeleton which correlates well to the higher catalytic activity at lower temperatures. To investigate functions of each individual amino acid position site-directed (saturation) mutagenesis were generated and screened. Amino acid positions Val249 and Ile321 were found to be crucial for improving activity and residue Ile13 (encoded by rare codon AUA) yields an improved expression level in E. coli.
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Affiliation(s)
- Chaoning Liang
- State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People's Republic of China
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42
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An alkali-halotolerant cellulase from Bacillus flexus isolated from green seaweed Ulva lactuca. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2010.08.069] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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43
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Rastogi G, Bhalla A, Adhikari A, Bischoff KM, Hughes SR, Christopher LP, Sani RK. Characterization of thermostable cellulases produced by Bacillus and Geobacillus strains. BIORESOURCE TECHNOLOGY 2010; 101:8798-806. [PMID: 20599378 DOI: 10.1016/j.biortech.2010.06.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 05/15/2010] [Accepted: 06/01/2010] [Indexed: 05/05/2023]
Abstract
The composition of thermophilic (60 degrees C) mixed cellulose-degrading enrichment culture initiated from compost samples was examined by constructing a 16S rRNA gene clone library and the presence of sequences related to Actinobacteria, Bacteroidetes, Chloroflexi, Deinococcus-Thermus, Firmicutes, and Proteobacteria were identified. Eight isolates capable of degrading cellulose, carboxymethyl cellulose (CMC), or ponderosa pine sawdust were identified as belonging to the genera Geobacillus, Thermobacillus, Cohnella, and Thermus. A compost isolate WSUCF1 (Geobacillus sp.) was selected based on its higher growth rate and cellulase activity compared to others in liquid minimal medium containing cellulose as a source of carbon and energy. Strain WSUCF1 and a previously isolated thermophilic cellulose-degrading deep gold mine strain DUSELR13 (Bacillus sp.) were examined for their enzyme properties and kinetics. The optimal pH for carboxymethyl cellulase (CMCase) activity was 5.0 for both isolates. The optimum temperatures for CMCase of WSUCFI and DUSELR13 were 70 and 75 degrees C, respectively. For CMC, the DUSELR13 and WSUCF1 CMCases had K(m) values of 3.11 and 1.08mg/ml, respectively. Most remarkably, WSUCF1 and DUSELR13 retained 89% and 78% of the initial CMCase activities, respectively, after incubation at 70 degrees C for 1day. These thermostable enzymes would facilitate development of more efficient and cost-effective forms of the simultaneous saccharification and fermentation process to convert lignocellulosic biomass into biofuels.
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Affiliation(s)
- Gurdeep Rastogi
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
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Cloning and characterization of a thermostable and halo-tolerant endoglucanase from Thermoanaerobacter tengcongensis MB4. Appl Microbiol Biotechnol 2010; 89:315-26. [DOI: 10.1007/s00253-010-2842-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/10/2010] [Accepted: 08/12/2010] [Indexed: 10/19/2022]
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