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Heng S, Sutheeworapong S, Wangnai C, Champreda V, Kosugi A, Ratanakhanokchai K, Tachaapaikoon C, Ceballos RM. Hydrolysis of ionic liquid-treated substrate with an Iocasia fonsfrigidae strain SP3-1 endoglucanase. Appl Microbiol Biotechnol 2024; 108:63. [PMID: 38189956 PMCID: PMC10774164 DOI: 10.1007/s00253-023-12918-1] [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: 07/26/2023] [Revised: 12/04/2023] [Accepted: 12/13/2023] [Indexed: 01/09/2024]
Abstract
Recently, we reported the discovery of a novel endoglucanase of the glycoside hydrolase family 12 (GH12), designated IfCelS12A, from the haloalkaliphilic anaerobic bacterium Iocasia fonsfrigidae strain SP3-1, which was isolated from a hypersaline pond in the Samut Sakhon province of Thailand (ca. 2017). IfCelS12A exhibits high substrate specificity on carboxymethyl cellulose and amorphous cellulose but low substrate specificity on b-1,3;1,4-glucan. Unlike some endoglucanases of the GH12 family, IfCelS12A does not exhibit hydrolytic activity on crystalline cellulose (i.e., Avicel™). High-Pressure Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC) analyses of products resulting from IfCelS12-mediated hydrolysis indicate mode of action for this enzyme. Notably, IfCelS12A preferentially hydrolyzes cellotetraoses, cellopentaoses, and cellohexaoses with negligible activity on cellobiose or cellotriose. Kinetic analysis with cellopentaose and barely b-D-glucan as cellulosic substrates were conducted. On cellopentaose, IfCelS12A demonstrates a 16-fold increase in activity (KM = 0.27 mM; kcat = 0.36 s-1; kcat/KM = 1.34 mM-1 s-1) compared to the enzymatic hydrolysis of barley b-D-glucan (KM: 0.04 mM, kcat: 0.51 s-1, kcat/KM = 0.08 mM-1 s-1). Moreover, IfCelS12A enzymatic efficacy is stable in hypersaline sodium chlorids (NaCl) solutions (up to 10% NaCl). Specifically, IfCel12A retains notable activity after 24 h at 2M NaCl (10% saline solution). IfCelS12A used as a cocktail component with other cellulolytic enzymes and in conjunction with mobile sequestration platform technology offers additional options for deconstruction of ionic liquid-pretreated cellulosic feedstock. KEY POINTS: • IfCelS12A from an anaerobic alkaliphile Iocasia fronsfrigidae shows salt tolerance • IfCelS12A in cocktails with other enzymes efficiently degrades cellulosic biomass • IfCelS12A used with mobile enzyme sequestration platforms enhances hydrolysis.
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Affiliation(s)
- Sobroney Heng
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
- Department of Molecular and Cell Biology, University of California, Merced, CA, 95343, USA
| | - Sawannee Sutheeworapong
- Systems Biology and Bioinformatics Laboratory, Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Chinnapong Wangnai
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Verawat Champreda
- National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Paholyothin Road Klong Luang, Pathumthani, 12120, Thailand
| | - Akihiko Kosugi
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Ibaraki, Japan
| | - Khanok Ratanakhanokchai
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
- Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Chakrit Tachaapaikoon
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand.
- Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand.
| | - Ruben Michael Ceballos
- Department of Molecular and Cell Biology, University of California, Merced, CA, 95343, USA.
- Quantitative Systems Biology Program, University of California, Merced, CA, 95343, USA.
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2
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Chen LB, OuYang YT, Liu L, Jin PJ, Huang RR, Pan WY, Wang Y, Xing JY, She TT, Jiao JY, Wang S, Li WJ. Methylobacterium nigriterrae sp. nov., isolated from black soil. Antonie Van Leeuwenhoek 2024; 117:83. [PMID: 38806744 DOI: 10.1007/s10482-024-01981-x] [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: 04/01/2024] [Accepted: 05/18/2024] [Indexed: 05/30/2024]
Abstract
An aerobic, Gram-stain-negative, motile rod bacterium, designated as SYSU BS000021T, was isolated from a black soil sample in Harbin, Heilongjiang province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Methylobacterium, and showed the highest sequence similarity to Methylobacterium segetis KCTC 62267 T (98.51%) and Methylobacterium oxalidis DSM 24028 T (97.79%). Growth occurred at 20-37℃ (optimum, 28 °C), pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 0% (w/v) NaCl. Polar lipids comprised of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid and one unidentified polar lipid. The major cellular fatty acids (> 5%) were C18:0 and C18:1 ω7c and/or C18:1 ω6c. The predominant respiratory quinone was Q-10. The genomic G + C content was 68.36% based on the whole genome analysis. The average nucleotide identity (≤ 83.5%) and digital DNA-DNA hybridization (≤ 27.3%) values between strain SYSU BS000021T and other members of the genus Methylobacterium were all lower than the threshold values recommended for distinguishing novel prokaryotic species. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain SYSU BS000021T represents a novel species of the genus Methylobacterium, for which the name Methylobacterium nigriterrae sp. nov. is proposed. The type strain of the proposed novel species is SYSU BS000021T (= GDMCC 1.3814 T = KCTC 8051 T).
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Affiliation(s)
- Le-Bin Chen
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Yu-Ting OuYang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Lan Liu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Pin-Jiao Jin
- Heilongjiang Academy of Black Soil Conservation & Utilization/Key Lab of Soil Environment and Plant Nutrition of Heilongjiang Province/Heilongjiang Fertilizer Engineering Research Center, Harbin, 150086, People's Republic of China
| | - Rong-Rong Huang
- School of Biology and Food Engineering, Guangdong University of Education, Guangzhou, 510303, People's Republic of China
| | - Wen-Yi Pan
- School of Biology and Food Engineering, Guangdong University of Education, Guangzhou, 510303, People's Republic of China
| | - Ying Wang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Jia-Ying Xing
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Ting-Ting She
- School of Biology and Food Engineering, Guangdong University of Education, Guangzhou, 510303, People's Republic of China
| | - Jian-Yu Jiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
| | - Shuang Wang
- Heilongjiang Academy of Black Soil Conservation & Utilization/Key Lab of Soil Environment and Plant Nutrition of Heilongjiang Province/Heilongjiang Fertilizer Engineering Research Center, Harbin, 150086, People's Republic of China.
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China.
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China.
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3
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Qiu Y, Johnson Z, Gu X, Bohutskyi P, Chen S. Dairy manure acidogenic fermentation at hyperthermophilic temperature enabled superior activity of thermostable hydrolytic enzymes linked to the genus Caldicoprobacter. BIORESOURCE TECHNOLOGY 2024; 391:129978. [PMID: 37944622 DOI: 10.1016/j.biortech.2023.129978] [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: 07/25/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023]
Abstract
In this study, fermentation experiments were conducted under mesophilic, thermophilic, and hyperthermophilic conditions to investigate adaptation of microbial communities and its effect on extracellular enzyme activities toward degradation of cellulose, hemicellulose and proteins in dairy manure. Hyperthermophilic conditions transformed the microbiome structure and stimulated activity of extracellular proteolytic, cellulolytic, and hemicellulolytic enzymes. Specifically, the activities of protease, cellulose 1,4-β-cellobiosidase, and β-glucosidase secreted by hyperthermophilic microbes were higher by 22%, 47% and 49% compared to those produced by mesophilic and thermophilic communities. Enhanced hydrolytic activity of hyperthermophilic microbes enabled improved feedstock solubilization and production of 39% and 22% more soluble COD than mesophilic and thermophilic microbes, respectively. Connections between hydrolytic function and microbial community structure at various temperatures were assessed using the PICRUSt2 computational tool. Genus Caldicoprobacter was identified as the primary candidate responsible for increased production of thermostable endo-1,4-β-glucanase, β-glucosidase and endo-1,4-β-xylanase, and enhanced hydrolytic performance of hyperthermophilic microbial community.
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Affiliation(s)
- Yaojing Qiu
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, United States
| | - Zachary Johnson
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, United States; Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, United States
| | - Xiangyu Gu
- State Key laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Pavlo Bohutskyi
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, United States; Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, United States.
| | - Shulin Chen
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, United States.
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4
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Yadav R, Vasundhara M, Rajamani T, Suryanarayanan TS, Reddy SM. Isolation and characterization of thermostable and alkali-tolerant cellulase from litter endophytic fungus Bartalinia pondoensis. Folia Microbiol (Praha) 2022; 67:955-964. [PMID: 35906455 DOI: 10.1007/s12223-022-00991-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/05/2022] [Indexed: 11/04/2022]
Abstract
Endophytic fungi in plant tissues produce a wide range of secondary metabolites and enzymes, which exhibit a variety of biological activities. In the present study, litter endophytic fungi were isolated from a fire-prone forest and screened for thermostable cellulases. Among nine endophytic fungi tested, two isolates, Bartalinia pondoensis and Phoma sp., showed the maximum cellulase activity. Bartalinia pondoensis was further selected for its cellulase production and characterization. Among the carbon and nitrogen sources tested, maximum cellulase production was observed with maltose and yeast extract, and the eucalyptus leaves and rice bran served as the best natural substrates. The cellulase activity increased with increasing temperature, with maximum activity recorded at 100 °C. The maximum CMCase activity was observed between pH 6.0 and 7.0 and retained 80% of its activity in the pH range of 8-10. Partially purified cellulase of B. pondoensis retained 50% of its activity after 2 h of incubation at 60 °C, 80 °C and 100 °C. These results suggest that litter endophytic fungus B. pondoensis is a potential source for the production of thermostable and alkali-tolerant cellulase.
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Affiliation(s)
- Rajnish Yadav
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala, 147004, Punjab, India
| | - Mondem Vasundhara
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala, 147004, Punjab, India
| | - Thavamani Rajamani
- Vivekananda Institute of Tropical Mycology (VINSTROM), Ramakrishna Mission Vidyapith, Chennai, 600004, Tamil Nadu, India
| | - Trichur S Suryanarayanan
- Vivekananda Institute of Tropical Mycology (VINSTROM), Ramakrishna Mission Vidyapith, Chennai, 600004, Tamil Nadu, India
| | - Sudhakara M Reddy
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala, 147004, Punjab, India.
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5
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Zhao ZY, Xia TT, Jiao JY, Liu L, Su QY, Li MM, Lv AP, Ouyang YT, Li WJ, Ming H. Qipengyuania thermophila sp. nov., isolated from a Chinese hot spring. Arch Microbiol 2022; 204:305. [PMID: 35532844 DOI: 10.1007/s00203-022-02927-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 11/02/2022]
Abstract
A novel Gram-stain-negative, non-motile, short rod-shaped and aerobic bacterial strain, designated as CFH 74456 T, was isolated from sediment of a hot spring, Tengchong, Yunnan Province, south-western China. Growth occurred at 20-53 ºC (optimum 45 ºC), pH 7.0-9.0 (optimum pH 8.0) and up to 2.0% (w/v) NaCl (optimum 0-1.0%, w/v). The predominant respiratory quinone was ubiquinone 10 (Q-10). The major fatty acids (> 10%) were C17:1 ω6c (17.9%) and summed feature 8 (38.6%). The polar lipid profile of strain CFH 74456 T was identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, three unidentified glycolipids and three unidentified polar lipids. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CFH 74456 T belongs to the genus Qipengyuania, and was most closely related to Qipengyuania sediminis CGMCC 1.12928 T (95.7%). The draft genome size of the isolate was 2.29 Mb with G + C content of 68.5%. The amino acid identity, average nucleotide identity and the digital DNA-DNA hybridization values between strain CFH 74456 T and the closest relatives ranged from 67.0 to 67.9%, 73.0 to 74.2% and 18.2-19.3%, respectively. On the basis of phenotypic, phylogenetic and genotypic analyses, it is concluded that strain CFH 74456 T represents a new species of the genus Qipengyuania, for which the name Qipengyuania thermophila sp. nov. is proposed. The type strain is CFH 74456 T (= KCTC 62921 T = CCTCC AB 2018237 T).
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Affiliation(s)
- Zi-Yu Zhao
- Synthetic Biology Engineering Lab of Henan Province, College of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, 453003, People's Republic of China
| | - Ting-Ting Xia
- Synthetic Biology Engineering Lab of Henan Province, College of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, 453003, People's Republic of China
| | - Jian-Yu Jiao
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Lan Liu
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Qing-Yang Su
- Synthetic Biology Engineering Lab of Henan Province, College of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, 453003, People's Republic of China
| | - Meng-Meng Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Ai-Ping Lv
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Yu-Ting Ouyang
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
| | - Hong Ming
- Synthetic Biology Engineering Lab of Henan Province, College of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, 453003, People's Republic of China.
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Abuajah CI, Ogbonna AC, Chukeze EJ, Ikpeme CA, Asogwa KK. A glucose oxidase peroxidase-coupled continuous assay protocol for the determination of cellulase activity in the laboratory. Anal Biochem 2022; 647:114649. [DOI: 10.1016/j.ab.2022.114649] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 02/01/2022] [Accepted: 03/09/2022] [Indexed: 11/01/2022]
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7
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Cutolo E, Tosoni M, Barera S, Herrera-Estrella L, Dall'Osto L, Bassi R. A chimeric hydrolase-PTXD transgene enables chloroplast-based heterologous protein expression and non-sterile cultivation of Chlamydomonas reinhardtii. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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8
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Thermostable cellulose saccharifying microbial enzymes: Characteristics, recent advances and biotechnological applications. Int J Biol Macromol 2021; 188:226-244. [PMID: 34371052 DOI: 10.1016/j.ijbiomac.2021.08.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/19/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022]
Abstract
Cellulases play a promising role in the bioconversion of renewable lignocellulosic biomass into fermentable sugars which are subsequently fermented to biofuels and other value-added chemicals. Besides biofuel industries, they are also in huge demand in textile, detergent, and paper and pulp industries. Low titres of cellulase production and processing are the main issues that contribute to high enzyme cost. The success of ethanol-based biorefinery depends on high production titres and the catalytic efficiency of cellulases functional at elevated temperatures with acid/alkali tolerance and the low cost. In view of their wider application in various industrial processes, stable cellulases that are active at elevated temperatures in the acidic-alkaline pH ranges, and organic solvents and salt tolerance would be useful. This review provides a recent update on the advances made in thermostable cellulases. Developments in their sources, characteristics and mechanisms are updated. Various methods such as rational design, directed evolution, synthetic & system biology and immobilization techniques adopted in evolving cellulases with ameliorated thermostability and characteristics are also discussed. The wide range of applications of thermostable cellulases in various industrial sectors is described.
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9
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Zafar A, Aftab MN, Asif A, Karadag A, Peng L, Celebioglu HU, Afzal MS, Hamid A, Iqbal I. Efficient biomass saccharification using a novel cellobiohydrolase from Clostridium clariflavum for utilization in biofuel industry. RSC Adv 2021; 11:9246-9261. [PMID: 35423428 PMCID: PMC8695235 DOI: 10.1039/d1ra00545f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/18/2021] [Accepted: 02/23/2021] [Indexed: 11/30/2022] Open
Abstract
The present study describes the cloning of the cellobiohydrolase gene from a thermophilic bacterium Clostridium clariflavum and its expression in Escherichia coli BL21(DE3) utilizing the expression vector pET-21a(+). The optimization of various parameters (pH, temperature, isopropyl β-d-1-thiogalactopyranoside (IPTG) concentration, time of induction) was carried out to obtain the maximum enzyme activity (2.78 ± 0.145 U ml−1) of recombinant enzyme. The maximum expression of recombinant cellobiohydrolase was obtained at pH 6.0 and 70 °C respectively. Enzyme purification was performed by heat treatment and immobilized metal anionic chromatography. The specific activity of the purified enzyme was 57.4 U mg−1 with 35.17% recovery and 3.90 purification fold. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight of cellobiohydrolase was 78 kDa. Among metal ions, Ca2+ showed a positive impact on the cellobiohydrolase enzyme with increased activity by 115%. Recombinant purified cellobiohydrolase enzyme remained stable and exhibited 77% and 63% residual activity in comparison to control in the presence of n-butanol and after incubation at 80 °C for 1 h, respectively. Our results indicate that our purified recombinant cellobiohydrolase can be used in the biofuel industry. Successful expression of a novel cellobiohydrolase enzyme from Clostridium clariflavum with efficient saccharification potential of plant biomass for the biofuel industry.![]()
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Affiliation(s)
- Asma Zafar
- Faculty of Life Sciences
- University of Central Punjab
- Lahore
- Pakistan
| | | | - Anam Asif
- Institute of Industrial Biotechnology
- GC University
- Lahore
- Pakistan
| | - Ahmet Karadag
- Department of Chemistry
- Faculty of Arts and Sciences
- Yozgat Bozok University
- Yozgat
- Turkey
| | - Liangcai Peng
- Biomass and Bioenergy Research Center
- Huazhong Agriculture University
- Wuhan
- China
| | | | - Muhammad Sohail Afzal
- Department of Life Sciences
- School of Science
- University of Management and Technology (UMT)
- Lahore
- Pakistan
| | - Attia Hamid
- Institute of Industrial Biotechnology
- GC University
- Lahore
- Pakistan
| | - Irfana Iqbal
- Department of Zoology
- Lahore College for Women University
- Lahore
- Pakistan
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10
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Benedetti M, Barera S, Longoni P, Guardini Z, Herrero Garcia N, Bolzonella D, Lopez‐Arredondo D, Herrera‐Estrella L, Goldschmidt‐Clermont M, Bassi R, Dall’Osto L. A microalgal-based preparation with synergistic cellulolytic and detoxifying action towards chemical-treated lignocellulose. PLANT BIOTECHNOLOGY JOURNAL 2021; 19:124-137. [PMID: 32649019 PMCID: PMC7769238 DOI: 10.1111/pbi.13447] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/19/2020] [Accepted: 06/28/2020] [Indexed: 05/28/2023]
Abstract
High-temperature bioconversion of lignocellulose into fermentable sugars has drawn attention for efficient production of renewable chemicals and biofuels, because competing microbial activities are inhibited at elevated temperatures and thermostable cell wall degrading enzymes are superior to mesophilic enzymes. Here, we report on the development of a platform to produce four different thermostable cell wall degrading enzymes in the chloroplast of Chlamydomonas reinhardtii. The enzyme blend was composed of the cellobiohydrolase CBM3GH5 from C. saccharolyticus, the β-glucosidase celB from P. furiosus, the endoglucanase B and the endoxylanase XynA from T. neapolitana. In addition, transplastomic microalgae were engineered for the expression of phosphite dehydrogenase D from Pseudomonas stutzeri, allowing for growth in non-axenic media by selective phosphite nutrition. The cellulolytic blend composed of the glycoside hydrolase (GH) domain GH12/GH5/GH1 allowed the conversion of alkaline-treated lignocellulose into glucose with efficiencies ranging from 14% to 17% upon 48h of reaction and an enzyme loading of 0.05% (w/w). Hydrolysates from treated cellulosic materials with extracts of transgenic microalgae boosted both the biogas production by methanogenic bacteria and the mixotrophic growth of the oleaginous microalga Chlorella vulgaris. Notably, microalgal treatment suppressed the detrimental effect of inhibitory by-products released from the alkaline treatment of biomass, thus allowing for efficient assimilation of lignocellulose-derived sugars by C. vulgaris under mixotrophic growth.
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Affiliation(s)
- Manuel Benedetti
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
- Present address:
Dipartimento MESVAUniversità dell'AquilaCoppitoAQItaly
| | - Simone Barera
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | - Paolo Longoni
- Faculty of ScienceInstitute of BiologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Zeno Guardini
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | | | | | - Damar Lopez‐Arredondo
- StelaGenomics MexicoS de RL de CVIrapuato, GuanajuatoMexico
- Institute of Genomics for Crop Abiotic Stress ToleranceTexas Tech UniversityLubbockTXUSA
| | - Luis Herrera‐Estrella
- Laboratorio Nacional de Genómica para la BiodiversidadCentro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalIrapuato, GuanajuatoMexico
- Institute of Genomics for Crop Abiotic Stress ToleranceTexas Tech UniversityLubbockTXUSA
| | | | - Roberto Bassi
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | - Luca Dall’Osto
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
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11
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Giovannoni M, Gramegna G, Benedetti M, Mattei B. Industrial Use of Cell Wall Degrading Enzymes: The Fine Line Between Production Strategy and Economic Feasibility. Front Bioeng Biotechnol 2020; 8:356. [PMID: 32411686 PMCID: PMC7200985 DOI: 10.3389/fbioe.2020.00356] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022] Open
Abstract
Cell Wall Degrading Enzymes (CWDEs) are a heterogeneous group of enzymes including glycosyl-hydrolases, oxidoreductases, lyases, and esterases. Microbes with degrading activities toward plant cell wall polysaccharides are the most relevant source of CWDEs for industrial applications. These organisms secrete a wide array of CWDEs in amounts strictly necessary for their own sustenance, nonetheless the production of CWDEs from wild type microbes can be increased at large-scale by using optimized fermentation strategies. In the last decades, advances in genetic engineering allowed the expression of recombinant CWDEs also in lab-domesticated organisms such as E. coli, yeasts and plants, dramatically increasing the available options for the large-scale production of CWDEs. The optimization of a CWDE-producing biofactory is a hard challenge that biotechnologists tackle by testing different expression strategies and expression-hosts. Although both the yield and production costs are critical factors to produce biomolecules at industrial scale, these parameters are often disregarded in basic research. This review presents the main characteristics and industrial applications of CWDEs directed toward the cell wall of plants, bacteria, fungi and microalgae. Different biofactories for CWDE expression are compared in order to highlight strengths and weaknesses of each production system and how these aspects impact the final enzyme cost and, consequently, the economic feasibility of using CWDEs for industrial applications.
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Affiliation(s)
- Moira Giovannoni
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Giovanna Gramegna
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Manuel Benedetti
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Benedetta Mattei
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
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12
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Thermostable endoglucanase gene derived by amplification from the genomic DNA of a cellulose-enriched mixed culture from mudspring water of Mt. Makiling, Laguna, Philippines. World J Microbiol Biotechnol 2020; 36:51. [PMID: 32157408 DOI: 10.1007/s11274-020-02825-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/29/2020] [Indexed: 10/24/2022]
Abstract
Culture-independent molecular-based approaches can be used to identify genes of interest from environmental sources that have desirable properties such as thermo activity. For this study, a putative thermo stable endoglucanase gene was identified from a mixed culture resulting from the inoculation of Brock-CMcellulose (1%) broth with mudspring water from Mt. Makiling, Laguna, Philippines that had been incubated at 90 °C. Genomic DNA was extracted from the cellulose-enriched mixed culture and endo1949 forward and reverse primers were used to amplify the endoglucanase gene, which was cloned into pCR-script plasmid vector. Blastn alignment of the sequenced insert revealed 99.69% similarity to the glycosyl hydrolase, sso1354 (CelA1; Q97YG7) from Saccharolobus solfataricus. The endoglucanase gene (GenBank accession number MK984682) was determined to be 1,021 nucleotide bases in length, corresponding to 333 amino acids with a molecular mass of ~ 37 kDa. The endoglucanase gene was inserted into a pET21 vector and transformed in E. coli BL21 for expression. Partially purified recombinant Mt. Makiling endoglucanase (MM-Engl) showed a specific activity of 187.61 U/mg and demonstrated heat stability up to 80 °C. The thermo-acid stable endoglucanase can be used in a supplementary hydrolysis step to further hydrolyze the lignocellulosic materials that were previously treated under high temperature-dilute acid conditions, thereby enhancing the release of more glucose sugars for bioethanol production.
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13
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Stokke R, Reeves EP, Dahle H, Fedøy AE, Viflot T, Lie Onstad S, Vulcano F, Pedersen RB, Eijsink VGH, Steen IH. Tailoring Hydrothermal Vent Biodiversity Toward Improved Biodiscovery Using a Novel in situ Enrichment Strategy. Front Microbiol 2020; 11:249. [PMID: 32153535 PMCID: PMC7046548 DOI: 10.3389/fmicb.2020.00249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 02/03/2020] [Indexed: 11/13/2022] Open
Abstract
Deep-sea hydrothermal vents are amongst the most extreme environments on Earth and represent interesting targets for marine bioprospecting and biodiscovery. The microbial communities in hydrothermal vents are often dominated by chemolithoautotrophs utilizing simple chemical compounds, though the full extent of their heterotrophic abilities is still being explored. In the bioprocessing industry, where degradation of complex organic materials often is a major challenge, new microbial solutions are heavily needed. To meet these needs, we have developed novel in situ incubators and tested if deployment of recalcitrant materials from fish farming and wood-pulping industries introduced changes in the microbial community structure in hot marine hydrothermal sediments. The incubation chambers were deployed in sediments at the Bruse vent site located within the Jan Mayen vent field for 1 year, after which the microbial populations in the chambers were profiled by 16S rRNA Ion Torrent amplicon sequencing. A total of 921 operational taxonomic units (OTUs) were assigned into 74 different phyla where differences in community structure were observed depending on the incubated material, chamber depth below the sea floor and/or temperature. A high fraction of putative heterotrophic microbial lineages related to cultivated members within the Thermotogales were observed. However, considerable fractions of previously uncultivated and novel Thermotogales and Bacteroidetes were also identified. Moreover, several novel lineages (e.g., members within the DPANN superphylum, unidentified archaeal lineages, unclassified Thermoplasmatales and Candidatus division BRC-1 bacterium) of as-yet uncultivated thermophilic archaea and bacteria were identified. Overall, our data illustrate that amendment of hydrothermal vent communities by in situ incubation of biomass induces shifts in community structure toward increased fractions of heterotrophic microorganisms. The technologies utilized here could aid in subsequent metagenomics-based enzyme discovery for diverse industries.
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Affiliation(s)
- Runar Stokke
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Eoghan P Reeves
- K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway.,Department of Earth Science, University of Bergen, Bergen, Norway
| | - Håkon Dahle
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Anita-Elin Fedøy
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Thomas Viflot
- K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway.,Department of Earth Science, University of Bergen, Bergen, Norway
| | - Solveig Lie Onstad
- K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway.,Department of Earth Science, University of Bergen, Bergen, Norway
| | - Francesca Vulcano
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Rolf B Pedersen
- K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway.,Department of Earth Science, University of Bergen, Bergen, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Ida H Steen
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Deep Sea Research, University of Bergen, Bergen, Norway
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Malik A, Kim YR, Jang IH, Hwang S, Oh DC, Kim SB. Genome-based analysis for the bioactive potential of Streptomyces yeochonensis CN732, an acidophilic filamentous soil actinobacterium. BMC Genomics 2020; 21:118. [PMID: 32013859 PMCID: PMC6998099 DOI: 10.1186/s12864-020-6468-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 01/08/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Acidophilic members of the genus Streptomyces can be a good source for novel secondary metabolites and degradative enzymes of biopolymers. In this study, a genome-based approach on Streptomyces yeochonensis CN732, a representative neutrotolerant acidophilic streptomycete, was employed to examine the biosynthetic as well as enzymatic potential, and also presence of any genetic tools for adaptation in acidic environment. RESULTS A high quality draft genome (7.8 Mb) of S. yeochonensis CN732 was obtained with a G + C content of 73.53% and 6549 protein coding genes. The in silico analysis predicted presence of multiple biosynthetic gene clusters (BGCs), which showed similarity with those for antimicrobial, anticancer or antiparasitic compounds. However, the low levels of similarity with known BGCs for most cases suggested novelty of the metabolites from those predicted gene clusters. The production of various novel metabolites was also confirmed from the combined high performance liquid chromatography-mass spectrometry analysis. Through comparative genome analysis with related Streptomyces species, genes specific to strain CN732 and also those specific to neutrotolerant acidophilic species could be identified, which showed that genes for metabolism in diverse environment were enriched among acidophilic species. In addition, the presence of strain specific genes for carbohydrate active enzymes (CAZyme) along with many other singletons indicated uniqueness of the genetic makeup of strain CN732. The presence of cysteine transpeptidases (sortases) among the BGCs was also observed from this study, which implies their putative roles in the biosynthesis of secondary metabolites. CONCLUSIONS This study highlights the bioactive potential of strain CN732, an acidophilic streptomycete with regard to secondary metabolite production and biodegradation potential using genomics based approach. The comparative genome analysis revealed genes specific to CN732 and also those among acidophilic species, which could give some insights into the adaptation of microbial life in acidic environment.
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Affiliation(s)
- Adeel Malik
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Yu Ri Kim
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - In Hee Jang
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Sunghoon Hwang
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong-Chan Oh
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seung Bum Kim
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, 34134, Republic of Korea.
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15
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Chu Y, Hao Z, Wang K, Tu T, Huang H, Wang Y, Bai YG, Wang Y, Luo H, Yao B, Su X. The GH10 and GH48 dual-functional catalytic domains from a multimodular glycoside hydrolase synergize in hydrolyzing both cellulose and xylan. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:279. [PMID: 31827607 PMCID: PMC6892212 DOI: 10.1186/s13068-019-1617-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/23/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Regarding plant cell wall polysaccharides degradation, multimodular glycoside hydrolases (GHs) with two catalytic domains separated by one or multiple carbohydrate-binding domains are rare in nature. This special mode of domain organization endows the Caldicellulosiruptor bescii CelA (GH9-CBM3c-CBM3b-CBM3b-GH48) remarkably high efficiency in hydrolyzing cellulose. CbXyn10C/Cel48B from the same bacterium is also such an enzyme which has, however, evolved to target both xylan and cellulose. Intriguingly, the GH10 endoxylanase and GH48 cellobiohydrolase domains are both dual functional, raising the question if they can act synergistically in hydrolyzing cellulose and xylan, the two major components of plant cell wall. RESULTS In this study, we discovered that CbXyn10C and CbCel48B, which stood for the N- and C-terminal catalytic domains, respectively, cooperatively released much more cellobiose and cellotriose from cellulose. In addition, they displayed intramolecular synergy but only at the early stage of xylan hydrolysis by generating higher amounts of xylooligosaccharides including xylotriose, xylotetraose, and xylobiose. When complex lignocellulose corn straw was used as the substrate, the synergy was found only for cellulose but not xylan hydrolysis. CONCLUSION This is the first report to reveal the synergy between a GH10 and a GH48 domain. The synergy discovered in this study is helpful for understanding how C. bescii captures energy from these recalcitrant plant cell wall polysaccharides. The insight also sheds light on designing robust and multi-functional enzymes for plant cell wall polysaccharides degradation.
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Affiliation(s)
- Yindi Chu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, 5# Dong Dan San Tiao, Beijing, 100005 China
| | - Zhenzhen Hao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Kaikai Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Tao Tu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Huoqing Huang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Yuan Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Ying Guo Bai
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Yaru Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
| | - Xiaoyun Su
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081 China
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16
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Basit A, Tajwar R, Sadaf S, Zhang Y, Akhtar MW. Improvement in activity of cellulase Cel12A of Thermotoga neapolitana by error prone PCR. J Biotechnol 2019; 306:118-124. [DOI: 10.1016/j.jbiotec.2019.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 11/15/2022]
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17
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Sahoo K, Sahoo RK, Gaur M, Subudhi E. Cellulolytic thermophilic microorganisms in white biotechnology: a review. Folia Microbiol (Praha) 2019; 65:25-43. [DOI: 10.1007/s12223-019-00710-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 04/15/2019] [Indexed: 10/26/2022]
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18
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Kumar S, Dangi AK, Shukla P, Baishya D, Khare SK. Thermozymes: Adaptive strategies and tools for their biotechnological applications. BIORESOURCE TECHNOLOGY 2019; 278:372-382. [PMID: 30709766 DOI: 10.1016/j.biortech.2019.01.088] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/19/2019] [Accepted: 01/21/2019] [Indexed: 05/10/2023]
Abstract
In today's scenario of global climate change, there is a colossal demand for sustainable industrial processes and enzymes from thermophiles. Plausibly, thermozymes are an important toolkit, as they are known to be polyextremophilic in nature. Small genome size and diverse molecular conformational modifications have been implicated in devising adaptive strategies. Besides, the utilization of chemical technology and gene editing attributions according to mechanical necessities are the additional key factor for efficacious bioprocess development. Microbial thermozymes have been extensively used in waste management, biofuel, food, paper, detergent, medicinal and pharmaceutical industries. To understand the strength of enzymes at higher temperatures different models utilize X-ray structures of thermostable proteins, machine learning calculations, neural networks, but unified adaptive measures are yet to be totally comprehended. The present review provides a recent updates on thermozymes and various interdisciplinary applications including the aspects of thermophiles bioengineering utilizing synthetic biology and gene editing tools.
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Affiliation(s)
- Sumit Kumar
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Arun K Dangi
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| | - Debabrat Baishya
- Department of Bioengineering and Technology, Institute of Science and Technology, Gauhati University, Guwahati 781014, Assam, India
| | - Sunil K Khare
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
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Benedetti M, Vecchi V, Betterle N, Natali A, Bassi R, Dall'Osto L. Design of a highly thermostable hemicellulose-degrading blend from Thermotoga neapolitana for the treatment of lignocellulosic biomass. J Biotechnol 2019; 296:42-52. [PMID: 30885654 DOI: 10.1016/j.jbiotec.2019.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 03/07/2019] [Accepted: 03/12/2019] [Indexed: 01/06/2023]
Abstract
The biological conversion of lignocellulose into fermentable sugars is a key process for the sustainable production of biofuels from plant biomass. Polysaccharides in plant feedstock can be valorized using thermostable mixtures of enzymes that degrade the cell walls, thus avoiding harmful and expensive pre-treatments. (Hyper)thermophilic bacteria of the phylum Thermotogae provide a rich source of enzymes for such industrial applications. Here we selected T. neapolitana as a source of hyperthermophilic hemicellulases for the degradation of lignocellulosic biomass. Two genes encoding putative hemicellulases were cloned from T. neapolitana genomic DNA and expressed in Escherichia coli. Further characterization revealed that the genes encoded an endo-1,4-β-galactanase and an α-l-arabinofuranosidase with optimal temperatures of ˜90 °C and high turnover numbers during catalysis (kcat values of ˜177 and ˜133 s-1, respectively, on soluble substrates). These enzymes were combined with three additional T. neapolitana hyperthermophilic hemicellulases - endo-1,4-β-xylanase (XynA), endo-1,4-β-mannanase (ManB/Man5A) and β-glucosidase (GghA) - to form a highly thermostable hemicellulolytic blend. The treatment of barley straw and corn bran with this enzymatic cocktail resulted in the solubilization of multiple hemicelluloses and boosted the yield of fermentable sugars by up to 65% when the complex substrates were further degraded by cellulases.
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Affiliation(s)
- Manuel Benedetti
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy
| | - Valeria Vecchi
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy
| | - Nico Betterle
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy.
| | - Alberto Natali
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy.
| | - Roberto Bassi
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy
| | - Luca Dall'Osto
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134, Verona, Italy.
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20
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Escuder-Rodríguez JJ, DeCastro ME, Cerdán ME, Rodríguez-Belmonte E, Becerra M, González-Siso MI. Cellulases from Thermophiles Found by Metagenomics. Microorganisms 2018; 6:microorganisms6030066. [PMID: 29996513 PMCID: PMC6165527 DOI: 10.3390/microorganisms6030066] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/04/2018] [Accepted: 07/05/2018] [Indexed: 01/05/2023] Open
Abstract
Cellulases are a heterogeneous group of enzymes that synergistically catalyze the hydrolysis of cellulose, the major component of plant biomass. Such reaction has biotechnological applications in a broad spectrum of industries, where they can provide a more sustainable model of production. As a prerequisite for their implementation, these enzymes need to be able to operate in the conditions the industrial process requires. Thus, cellulases retrieved from extremophiles, and more specifically those of thermophiles, are likely to be more appropriate for industrial needs in which high temperatures are involved. Metagenomics, the study of genes and gene products from the whole community genomic DNA present in an environmental sample, is a powerful tool for bioprospecting in search of novel enzymes. In this review, we describe the cellulolytic systems, we summarize their biotechnological applications, and we discuss the strategies adopted in the field of metagenomics for the discovery of new cellulases, focusing on those of thermophilic microorganisms.
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Affiliation(s)
- Juan-José Escuder-Rodríguez
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - María-Eugenia DeCastro
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - María-Esperanza Cerdán
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - Esther Rodríguez-Belmonte
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - Manuel Becerra
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
| | - María-Isabel González-Siso
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Departamento de Bioloxía, Facultade de Ciencias, Universidade da Coruña, 15071 A Corunna, Spain.
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21
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Xiao Y, He X, Ojeda-Lassalle Y, Poovaiah C, Coleman HD. Expression of a hyperthermophilic endoglucanase in hybrid poplar modifies the plant cell wall and enhances digestibility. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:225. [PMID: 30147748 PMCID: PMC6094567 DOI: 10.1186/s13068-018-1224-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/06/2018] [Indexed: 05/02/2023]
Abstract
BACKGROUND Expression of glycosyl hydrolases in lignocellulosic biomass has been proposed as an alternative to improve efficiency of cellulosic ethanol production. In planta production of hyperthermophilic hydrolytic enzymes could prevent the detrimental effects often seen resulting from the expression of recombinant mesophilic enzymes to plant hosts. Utilizing lignocellulosic feedstocks to produce hyperthermophilic hydrolases provides additional benefits for ethanol production in the way of transgenic feedstocks serving as both enzyme providers and cellulosic substrates. RESULTS In this study, transgenic hybrid poplar (Populus alba × grandidentata) was generated to express a hyperthermophilic endoglucanase from Thermotoga neapolitana with an optimal temperature over 100 °C. Functional hyperthermoactive endoglucanase was successfully produced in the transgenic events, and altered phenotypic growth was observed in transgenic lines. Moreover, the line with the highest TnCelB expression in both leaf and developing xylem had reduced lignin content and cellulose crystallinity, resulting in a more digestible cell wall. The activation of TnCelB by a post-harvest heat treatment resulted in enhanced saccharification efficiencies of transgenic poplar lines with moderate TnCelB expression and without alteration of cellulose and lignin when not heat-treated. In planta high-level overexpression of a hyperthermophilic endoglucanase paired with heat treatment following harvest, resulted in biomass that was comparable with wild-type lines that underwent a traditional pretreatment for saccharification. CONCLUSIONS Overexpression of hyperthermophilic endoglucanase in feedstock had impacts on plant growth and cell wall composition, especially when the enzyme was highly expressed. Improved glucan saccharification efficiencies from transgenic lines before and after heat treatment could reduce both the economic and environmental costs associated with ethanol production from lignocellulosic biomass.
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Affiliation(s)
- Yao Xiao
- Biology Department, Syracuse University, Syracuse, NY 13244 USA
| | - Xuejun He
- Biology Department, Syracuse University, Syracuse, NY 13244 USA
| | | | - Charleson Poovaiah
- Biology Department, Syracuse University, Syracuse, NY 13244 USA
- Present Address: Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua, 3010 New Zealand
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Xue DS, Liang LY, Lin DQ, Yao SJ. Thermal Inactivation Kinetics and Secondary Structure Change of a Low Molecular Weight Halostable Exoglucanase from a Marine Aspergillus niger at High Salinities. Appl Biochem Biotechnol 2017; 183:1111-1125. [PMID: 28488121 DOI: 10.1007/s12010-017-2487-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/19/2017] [Indexed: 11/25/2022]
Abstract
Two kinds of exoglucanase were purified from a marine Aspergillus niger. Catalytic ability of halophilic exoglucanase with a lower molecular weight and secondary structure change was analyzed at different salinities. Activity of the low molecular weight exoglucanase in 10% NaCl solution (w/v) was 1.69-fold higher of that in NaCl-free solution. Half-life time in 10% NaCl solution (w/v) was over 1.27-fold longer of that in NaCl-free solution. Free energy change of the low molecular weight exoglucanase denaturation, △G, in 10% NaCl solution (w/v) was 0.54 kJ/mol more than that in NaCl-free solution. Melt point in 10% NaCl solution (w/v), 52.01 °C, was 4.21 °C higher than that in NaCl-free solution, 47.80 °C. K m value, 0.179 mg/ml in 10% NaCl solution (w/v) was less 0.044 mg/ml than that, 0.224 mg/ml, in NaCl-free solution. High salinity made content of α-helix increased. Secondary structure change caused by high salinities improved exoglucanase thermostability and catalysis activity. The halophilic exoglucanase from a marine A. niger was valuable for hydrolyzing cellulose at high salinities.
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Affiliation(s)
- Dong-Sheng Xue
- Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, People's Republic of China
| | - Long-Yuan Liang
- Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, People's Republic of China
| | - Dong-Qiang Lin
- Department of Chemical and Bioengineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Shan-Jing Yao
- Department of Chemical and Bioengineering, Zhejiang University, Hangzhou, 310027, People's Republic of China.
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Gomes E, de Souza AR, Orjuela GL, Da Silva R, de Oliveira TB, Rodrigues A. Applications and Benefits of Thermophilic Microorganisms and Their Enzymes for Industrial Biotechnology. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_21] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Peng X, Su H, Mi S, Han Y. A multifunctional thermophilic glycoside hydrolase from Caldicellulosiruptor owensensis with potential applications in production of biofuels and biochemicals. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:98. [PMID: 27141233 PMCID: PMC4852416 DOI: 10.1186/s13068-016-0509-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/14/2016] [Indexed: 05/16/2023]
Abstract
BACKGROUND Thermophilic enzymes have attracted much attention for their advantages of high reaction velocity, exceptional thermostability, and decreased risk of contamination. Exploring efficient thermophilic glycoside hydrolases will accelerate the industrialization of biofuels and biochemicals. RESULTS A multifunctional glycoside hydrolase (GH) CoGH1A, belonging to GH1 family with high activities of β-d-glucosidase, exoglucanase, β-d-xylosidase, β-d-galactosidase, and transgalactosylation, was cloned and expressed from the extremely thermophilic bacterium Caldicellulosiruptor owensensis. The enzyme exerts excellent thermostability by retaining 100 % activity after 12-h incubation at 75 °C. The catalytic coefficients (k cat/K m) of the enzyme against pNP-β-D-galactopyranoside, pNP-β-D-glucopyranoside, pNP-β-D-cellobioside, pNP-β-D-xylopyranoside, and cellobiose were, respectively, 7450.0, 2467.5, 1085.4, 90.9, and 137.3 mM(-1) s(-1). When CoGH1A was supplemented at the dosage of 20 Ucellobiose g(-1) biomass for hydrolysis of the pretreated corn stover, comparing with the control, the glucose and xylose yields were, respectively, increased 37.9 and 42.1 %, indicating that the enzyme contributed not only for glucose but also for xylose release. The efficiencies of lactose decomposition and synthesis of galactooligosaccharides (GalOS) by CoGH1A were investigated at low (40 g L(-1)) and high (500 g L(-1)) initial lactose concentrations. At low lactose concentration, the time for decomposition of 83 % lactose was 10 min, which is much shorter than the reported 2-10 h for reaching such a decomposition rate. At high lactose concentration, after 50-min catalysis, the GalOS concentration reached 221 g L(-1) with a productivity of 265.2 g L(-1) h(-1). This productivity is at least 12-fold higher than those reported in literature. CONCLUSIONS The multifunctional glycoside hydrolase CoGH1A has high capabilities in saccharification of lignocellulosic biomass, decomposition of lactose, and synthesis of galactooligosaccharides. It is a promising enzyme to be used for bioconversion of carbohydrates in industrial scale. In addition, the results of this study indicate that the extremely thermophilic bacteria are potential resources for screening highly efficient glycoside hydrolases for the production of biofuels and biochemicals.
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Affiliation(s)
- Xiaowei Peng
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Hong Su
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Shuofu Mi
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Yejun Han
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
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Zhang X, Wang S, Wu X, Liu S, Li D, Xu H, Gao P, Chen G, Wang L. Subsite-specific contributions of different aromatic residues in the active site architecture of glycoside hydrolase family 12. Sci Rep 2015; 5:18357. [PMID: 26670009 PMCID: PMC4680936 DOI: 10.1038/srep18357] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 11/16/2015] [Indexed: 01/22/2023] Open
Abstract
The active site architecture of glycoside hydrolase (GH) is a contiguous subregion of the enzyme constituted by residues clustered in the three-dimensional space, recognizing the monomeric unit of ligand through hydrogen bonds and hydrophobic interactions. Mutations of the key residues in the active site architecture of the GH12 family exerted different impacts on catalytic efficiency. Binding affinities between the aromatic amino acids and carbohydrate rings were quantitatively determined by isothermal titration calorimetry (ITC) and the quantum mechanical (QM) method, showing that the binding capacity order of Tyr>Trp>His (and Phe) was determined by their side-chain properties. The results also revealed that the binding constant of a certain residue remained unchanged when altering its location, while the catalytic efficiency changed dramatically. Increased binding affinity at a relatively distant subsite, such as the mutant of W7Y at the -4 subsite, resulted in a marked increase in the intermediate product of cellotetraose and enhanced the reactivity of endoglucanase by 144%; while tighter binding near the catalytic center, i.e. W22Y at the -2 subsite, enabled the enzyme to bind and hydrolyze smaller oligosaccharides. Clarification of the specific roles of the aromatics at different subsites may pave the way for a more rational design of GHs.
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Affiliation(s)
- Xiaomei Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Shuai Wang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Xiuyun Wu
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Shijia Liu
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Dandan Li
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Hao Xu
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100, P.R. China
| | - Peiji Gao
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Guanjun Chen
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
| | - Lushan Wang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, P.R. China
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Wang J, Gao G, Li Y, Yang L, Liang Y, Jin H, Han W, Feng Y, Zhang Z. Cloning, Expression, and Characterization of a Thermophilic Endoglucanase, AcCel12B from Acidothermus cellulolyticus 11B. Int J Mol Sci 2015; 16:25080-95. [PMID: 26506341 PMCID: PMC4632791 DOI: 10.3390/ijms161025080] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/29/2015] [Accepted: 10/13/2015] [Indexed: 12/23/2022] Open
Abstract
The gene ABK52392 from the thermophilic bacterium Acidothermus cellulolyticus 11B was predicted to be endoglucanase and classified into glycoside hydrolase family 12. ABK52392 encodes a protein containing a catalytic domain and a carbohydrate binding module. ABK52392 was cloned and functionally expressed in Escherichia coli. After purification by Ni-NTA agarose affinity chromatography and Q-Sepharose® Fast Flow chromatography, the properties of the recombinant protein (AcCel12B) were characterized. AcCel12B exhibited optimal activity at pH 4.5 and 75 °C. The half-lives of AcCel12B at 60 and 70 °C were about 90 and 2 h, respectively, under acidic conditions. The specific hydrolytic activities of AcCel12B at 70 °C and pH 4.5 for sodium carboxymethylcellulose (CMC) and regenerated amorphous cellulose (RAC) were 118.3 and 104.0 U·mg−1, respectively. The Km and Vmax of AcCel12B for CMC were 25.47 mg·mL−1 and 131.75 U·mg−1, respectively. The time course of hydrolysis for RAC was investigated by measuring reducing ends in the soluble and insoluble phases. The total hydrolysis rate rapidly decreased after the early stage of incubation and the generation of insoluble reducing ends decreased earlier than that of soluble reducing ends. High thermostability of the cellulase indicates its potential commercial significance and it could be exploited for industrial application in the future.
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Affiliation(s)
- Junling Wang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
- Department of Biotechnology, Jilin Agricultural Science and Technology College, Jilin 132101, China.
| | - Gui Gao
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Yuwei Li
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
| | - Liangzhen Yang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Yanli Liang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Hanyong Jin
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Weiwei Han
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Yan Feng
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
| | - Zuoming Zhang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
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27
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Isolation of Fungi and Bacteria Associated with the Guts of Tropical Wood-Feeding Coleoptera and Determination of Their Lignocellulolytic Activities. Int J Microbiol 2015; 2015:285018. [PMID: 26379709 PMCID: PMC4563095 DOI: 10.1155/2015/285018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 08/12/2015] [Indexed: 12/22/2022] Open
Abstract
The guts of beetle larvae constitute a complex system where relationships among fungi, bacteria, and the insect host occur. In this study, we collected larvae of five families of wood-feeding Coleoptera in tropical forests of Costa Rica, isolated fungi and bacteria from their intestinal tracts, and determined the presence of five different pathways for lignocellulolytic activity. The fungal isolates were assigned to three phyla, 16 orders, 24 families, and 40 genera; Trichoderma was the most abundant genus, detected in all insect families and at all sites. The bacterial isolates were assigned to five phyla, 13 orders, 22 families, and 35 genera; Bacillus, Serratia, and Pseudomonas were the dominant genera, present in all the Coleopteran families. Positive results for activities related to degradation of wood components were determined in 65% and 48% of the fungal and bacterial genera, respectively. Our results showed that both the fungal and bacterial populations were highly diverse in terms of number of species and their phylogenetic composition, although the structure of the microbial communities varied with insect host family and the surrounding environment. The recurrent identification of some lignocellulolytic-positive inhabitants suggests that particular microbial groups play important roles in providing nutritional needs for the Coleopteran host.
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28
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Expression of Heterologous Cellulases in Thermotoga sp. Strain RQ2. BIOMED RESEARCH INTERNATIONAL 2015; 2015:304523. [PMID: 26273605 PMCID: PMC4529897 DOI: 10.1155/2015/304523] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 01/21/2015] [Accepted: 02/06/2015] [Indexed: 11/18/2022]
Abstract
The ability of Thermotoga spp. to degrade cellulose is limited due to a lack of exoglucanases. To address this deficiency, cellulase genes Csac_1076 (celA) and Csac_1078 (celB) from Caldicellulosiruptor saccharolyticus were cloned into T. sp. strain RQ2 for heterologous overexpression. Coding regions of Csac_1076 and Csac_1078 were fused to the signal peptide of TM1840 (amyA) and TM0070 (xynB), resulting in three chimeric enzymes, namely, TM1840-Csac_1078, TM0070-Csac_1078, and TM0070-Csac_1076, which were carried by Thermotoga-E. coli shuttle vectors pHX02, pHX04, and pHX07, respectively. All three recombinant enzymes were successfully expressed in E. coli DH5α and T. sp. strain RQ2, rendering the hosts with increased endo- and/or exoglucanase activities. In E. coli, the recombinant enzymes were mainly bound to the bacterial cells, whereas in T. sp. strain RQ2, about half of the enzyme activities were observed in the culture supernatants. However, the cellulase activities were lost in T. sp. strain RQ2 after three consecutive transfers. Nevertheless, this is the first time heterologous genes bigger than 1 kb (up to 5.3 kb in this study) have ever been expressed in Thermotoga, demonstrating the feasibility of using engineered Thermotoga spp. for efficient cellulose utilization.
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29
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Solaiman DK, Ashby RD, Crocker NV. High-titer production and strong antimicrobial activity of sophorolipids fromRhodotorula bogoriensis. Biotechnol Prog 2015; 31:867-74. [DOI: 10.1002/btpr.2101] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 04/29/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Daniel K.Y. Solaiman
- Biobased and Other Animal Co-Products Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture; Wyndmoor PA 19038
| | - Richard D. Ashby
- Biobased and Other Animal Co-Products Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture; Wyndmoor PA 19038
| | - Nicole V. Crocker
- Biobased and Other Animal Co-Products Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture; Wyndmoor PA 19038
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30
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Payne CM, Knott BC, Mayes HB, Hansson H, Himmel ME, Sandgren M, Ståhlberg J, Beckham GT. Fungal Cellulases. Chem Rev 2015; 115:1308-448. [DOI: 10.1021/cr500351c] [Citation(s) in RCA: 533] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christina M. Payne
- Department
of Chemical and Materials Engineering and Center for Computational
Sciences, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, Kentucky 40506, United States
| | - Brandon C. Knott
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Heather B. Mayes
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Henrik Hansson
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Michael E. Himmel
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mats Sandgren
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Jerry Ståhlberg
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Gregg T. Beckham
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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31
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The characterization of the endoglucanase Cel12A from Gloeophyllum trabeum reveals an enzyme highly active on β-glucan. PLoS One 2014; 9:e108393. [PMID: 25251390 PMCID: PMC4177221 DOI: 10.1371/journal.pone.0108393] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 08/21/2014] [Indexed: 11/19/2022] Open
Abstract
The basidiomycete fungus Gloeophyllum trabeum causes a typical brown rot and is known to use reactive oxygen species in the degradation of cellulose. The extracellular Cel12A is one of the few endo-1,4-β-glucanase produced by G. trabeum. Here we cloned cel12A and heterologously expressed it in Aspergillus niger. The identity of the resulting recombinant protein was confirmed by mass spectrometry. We used the purified GtCel12A to determine its substrate specificity and basic biochemical properties. The G. trabeum Cel12A showed highest activity on β-glucan, followed by lichenan, carboxymethylcellulose, phosphoric acid swollen cellulose, microcrystalline cellulose, and filter paper. The optimal pH and temperature for enzymatic activity were, respectively, 4.5 and 50°C on β-glucan. Under these conditions specific activity was 239.2±9.1 U mg−1 and the half-life of the enzyme was 84.6±3.5 hours. Thermofluor studies revealed that the enzyme was most thermal stable at pH 3. Using β-glucan as a substrate, the Km was 3.2±0.5 mg mL−1 and the Vmax was 0.41±0.02 µmol min−1. Analysis of the effects of GtCel12A on oat spelt and filter paper by scanning electron microscopy revealed the morphological changes taking place during the process.
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32
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SAXS Studies of the Endoglucanase Cel12A from Gloeophyllum trabeum Show Its Monomeric Structure and Reveal the Influence of Temperature on the Structural Stability of the Enzyme. MATERIALS 2014; 7:5202-5211. [PMID: 28788125 PMCID: PMC5455812 DOI: 10.3390/ma7075202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/10/2014] [Accepted: 06/24/2014] [Indexed: 11/21/2022]
Abstract
Endoglucanases are key enzymes applied to the conversion of biomass aiming for second generation biofuel production. In the present study we obtained the small angle X-ray scattering (SAXS) structure of the G. trabeumendo-1,4-β-glucanase Cel12A and investigated the influence of an important parameter, temperature, on both secondary and tertiary structure of the enzyme and its activity. The CD analysis for GtCel12A revealed that changes in the CD spectra starts at 55 °C and the Tm calculated from the experimental CD sigmoid curve using the Boltzmann function was 60.2 ± 0.6 °C. SAXS data showed that GtCel12A forms monomers in solution and has an elongated form with a maximum diameter of 60 ± 5 Å and a gyration radius of 19.4 ± 0.1 Å as calculated from the distance distribution function. Kratky analysis revealed that 60 °C is the critical temperature above which we observed clear indications of denaturation. Our results showed the influence of temperature on the stability and activity of enzymes and revealed novel structural features of GtCel12A.
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33
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Wang K, Luo H, Bai Y, Shi P, Huang H, Xue X, Yao B. A thermophilic endo-1,4-β-glucanase from Talaromyces emersonii CBS394.64 with broad substrate specificity and great application potentials. Appl Microbiol Biotechnol 2014; 98:7051-60. [DOI: 10.1007/s00253-014-5680-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/05/2014] [Accepted: 03/09/2014] [Indexed: 10/25/2022]
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34
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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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35
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Members of the Order Thermotogales: From Microbiology to Hydrogen Production. MICROBIAL BIOENERGY: HYDROGEN PRODUCTION 2014. [DOI: 10.1007/978-94-017-8554-9_9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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36
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Jun SY, Kim JS, Choi KH, Cha J, Ha NC. Structure of a novel α-amylase AmyB fromThermotoga neapolitanathat produces maltose from the nonreducing end of polysaccharides. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:442-50. [DOI: 10.1107/s0907444912049219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/30/2012] [Indexed: 11/11/2022]
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37
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Tran CTH, Nosworthy NJ, Kondyurin A, McKenzie DR, Bilek MMM. CelB and β-glucosidase immobilization for carboxymethyl cellulose hydrolysis. RSC Adv 2013. [DOI: 10.1039/c3ra43666g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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38
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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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Carbohydrate hydrolysis and transport in the extreme thermoacidophile Sulfolobus solfataricus. Appl Environ Microbiol 2012; 78:7931-8. [PMID: 22941087 DOI: 10.1128/aem.01758-12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Extremely thermoacidophilic microbes, such as Sulfolobus solfataricus, are strict chemoheterotrophs despite their geologic niche. To clarify their ecophysiology, the overlapping roles of endoglucanases and carbohydrate transporters were examined during growth on soluble cellodextrins as the sole carbon and energy source. Strain-specific differences in genome structure implied a unique role for one of three endogenous endoglucanases. Plasmid-based endoglucanase expression promoted the consumption of oligosaccharides, including cellohexaose (G6) through cellonanaose (G9). Protein transporters required for cellodextrin uptake were identified through mutagenesis and complementation of an ABC transporter cassette, including a putative oligosaccharide binding protein. In addition, ablation of the binding protein compromised growth on glucose and alpha-linked oligosaccharides while inactivation of a previously described glucose transporter had no apparent impact. These data demonstrate that S. solfataricus employs a redundant mechanism for soluble cellodextrin catabolism having both substrate uptake and extracytoplasmic hydrolytic components.
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40
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Xue DS, Chen HY, Ren YR, Yao SJ. Enhancing the activity and thermostability of thermostable β-glucosidase from a marine Aspergillus niger at high salinity. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.12.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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41
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Expression of novel β-glucanase Cel12A from Stachybotrys atra in bacterial and fungal hosts. Fungal Biol 2012; 116:443-51. [PMID: 22385626 DOI: 10.1016/j.funbio.2012.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 01/12/2012] [Accepted: 01/17/2012] [Indexed: 11/23/2022]
Abstract
β-glucanase Cel12A from Stachybotrys atra has been cloned and expressed in Aspergillus niger. The purified enzyme showed high activity of β-1,3-1,4-mixed glucans, was also active on carboxymethylcellulose (CMC), while it did not hydrolyze crystalline cellulose or β-1,3 glucans as laminarin. Cel12A showed a marked substrate preference for β-1,3-1,4 glucans, showing maximum activity on barley β-glucans (27.69 U mg(-1)) while the activity on CMC was much lower (0.51 U mg(-1)). Analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focussing (IEF), and zymography showed the recombinant enzyme has apparent molecular weight of 24 kDa and a pI of 8.2. Optimal temperature and pH for enzyme activity were 50°C and pH 6.5. Thin layer chromatography analysis showed that major hydrolysis products from barley β-glucan and lichean were 3-O-β-cellotriosyl-D-glucose and 3-O-β-cellobiosyl-D-glucose, while glucose and cellobiose were released in smaller amounts. The amino acid sequence deduced from cel12A revealed that it is a single domain enzyme belonging to the GH12 family, a family that contains several endoglucanases with substrate preference for β-1,3-1,4 glucans. We believe that S. atra Cel12A should be considered as a lichenase-like or nontypical endoglucanase.
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Biochemical and mutational analyses of a multidomain cellulase/mannanase from Caldicellulosiruptor bescii. Appl Environ Microbiol 2012; 78:2230-40. [PMID: 22247178 DOI: 10.1128/aem.06814-11] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Thermophilic cellulases and hemicellulases are of significant interest to the biofuel industry due to their perceived advantages over their mesophilic counterparts. We describe here biochemical and mutational analyses of Caldicellulosiruptor bescii Cel9B/Man5A (CbCel9B/Man5A), a highly thermophilic enzyme. As one of the highly secreted proteins of C. bescii, the enzyme is likely to be critical to nutrient acquisition by the bacterium. CbCel9B/Man5A is a modular protein composed of three carbohydrate-binding modules flanked at the N terminus and the C terminus by a glycoside hydrolase family 9 (GH9) module and a GH5 module, respectively. Based on truncational analysis of the polypeptide, the cellulase and mannanase activities within CbCel9B/Man5A were assigned to the N- and C-terminal modules, respectively. CbCel9B/Man5A and its truncational mutants, in general, exhibited a pH optimum of ∼5.5 and a temperature optimum of 85°C. However, at this temperature, thermostability was very low. After 24 h of incubation at 75°C, the wild-type protein maintained 43% activity, whereas a truncated mutant, TM1, maintained 75% activity. The catalytic efficiency with phosphoric acid swollen cellulose as a substrate for the wild-type protein was 7.2 s(-1) ml/mg, and deleting the GH5 module led to a mutant (TM1) with a 2-fold increase in this kinetic parameter. Deletion of the GH9 module also increased the apparent k(cat) of the truncated mutant TM5 on several mannan-based substrates; however, a concomitant increase in the K(m) led to a decrease in the catalytic efficiencies on all substrates. These observations lead us to postulate that the two catalytic activities are coupled in the polypeptide.
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Wang Y, Wang X, Tang R, Yu S, Zheng B, Feng Y. A novel thermostable cellulase from Fervidobacterium nodosum. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2010.06.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Teng Y, Yin Q, ding M, Zhao F. Purification and characterization of a novel endo-β-1,4-glucanases , AfEG22, from the giant snail, Achatina fulica frussac. Acta Biochim Biophys Sin (Shanghai) 2010; 42:729-34. [PMID: 20870931 DOI: 10.1093/abbs/gmq083] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, we confirmed that at least three endo-β-1,4-glucanases existed in the digestive juice of the giant snail, Achatina fulica ferussac, by Congo red staining assay. One of these enzymes, a novel endo-β-1,4-glucanase (AfEG22), was purified 29.5-fold by gel filtration, anion exchange, and hydrophobic interaction chromatography. The carboxymethyl cellulose (CMC) hydrolytic activity of the purified enzyme was 12.3 U/mg protein. The molecular mass of AfEG22 was 22081 Da determined by MALDI-TOF. N-terminal amino acid sequencing revealed a sequence of EQRCTNQGGILKYYNT, which did not have significant homology with any proteins in BLAST database. The optimal pH and temperature for hydrolytic activity toward CMC were pH 4.0 and 50°C, respectively. AfEG22 was stable between pH 3.0 and pH 12.0 when incubated at 4°C for 3 h or at 37°C for 1 h. The enzyme remained more than 80% activity between pH 4.5 and pH 7.0 after incubation at 50°C for 1 h. AfEG22 possessed excellent thermostability as more than 70% activity was remained after incubation at 60°C for 3 h. Substrate specific analysis revealed that AfEG22 was a typical endo-β-1,4-glucanase. This is the first time to report a novel endo-β-1,4-glucanase with high stability from the digestive juice of A. fulica.
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Affiliation(s)
- Yigang Teng
- Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China
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de Carvalho CCCR. Enzymatic and whole cell catalysis: finding new strategies for old processes. Biotechnol Adv 2010; 29:75-83. [PMID: 20837129 DOI: 10.1016/j.biotechadv.2010.09.001] [Citation(s) in RCA: 193] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 09/06/2010] [Indexed: 10/19/2022]
Abstract
The use of enzymes and whole bacterial cells has allowed the production of a plethora of compounds that have been used for centuries in foods and beverages. However, only recently we have been able to master techniques that allow the design and development of new biocatalysts with high stability and productivity. Rational redesign and directed evolution have lead to engineered enzymes with new characteristics whilst the understanding of adaptation mechanisms in bacterial cells has allowed their use under new operational conditions. Bacteria able to thrive under the most extreme conditions have also provided new and extraordinary catalytic processes. In this review, the new tools available for the improvement of biocatalysts are presented and discussed.
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Affiliation(s)
- Carla C C R de Carvalho
- IBB-Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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Yeoman CJ, Han Y, Dodd D, Schroeder CM, Mackie RI, Cann IKO. Thermostable enzymes as biocatalysts in the biofuel industry. ADVANCES IN APPLIED MICROBIOLOGY 2010; 70:1-55. [PMID: 20359453 DOI: 10.1016/s0065-2164(10)70001-0] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Lignocellulose is the most abundant carbohydrate source in nature and represents an ideal renewable energy source. Thermostable enzymes that hydrolyze lignocellulose to its component sugars have significant advantages for improving the conversion rate of biomass over their mesophilic counterparts. We review here the recent literature on the development and use of thermostable enzymes for the depolymerization of lignocellulosic feedstocks for biofuel production. Furthermore, we discuss the protein structure, mechanisms of thermostability, and specific strategies that can be used to improve the thermal stability of lignocellulosic biocatalysts.
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Affiliation(s)
- Carl J Yeoman
- Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
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Park KM, Jun SY, Choi KH, Park KH, Park CS, Cha J. Characterization of an exo-acting intracellular alpha-amylase from the hyperthermophilic bacterium Thermotoga neapolitana. Appl Microbiol Biotechnol 2009; 86:555-66. [PMID: 19834705 DOI: 10.1007/s00253-009-2284-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 09/27/2009] [Accepted: 09/29/2009] [Indexed: 10/20/2022]
Abstract
We cloned and expressed the gene for an intracellular alpha-amylase, designated AmyB, from the hyperthermophilic bacterium Thermotoga neapolitana in Escherichia coli. The putative intracellular amylolytic enzyme contained four regions that are highly conserved among glycoside hydrolase family (GH) 13 alpha-amylases. AmyB exhibited maximum activity at pH 6.5 and 75 degrees C, and its thermostability was slightly enhanced by Ca2+. However, Ca2+ was not required for the activity of AmyB as EDTA had no effect on enzyme activity. AmyB hydrolyzed the typical substrates for alpha-amylase, including soluble starch, amylose, amylopectin, and glycogen, to liberate maltose and minor amount of glucose. The hydrolytic pattern of AmyB is most similar to those of maltogenic amylases (EC 3.2.1.133) among GH 13 alpha-amylases; however, it can be distinguished by its inability to hydrolyze pullulan and beta-cyclodextrin. AmyB enzymatic activity was negligible when acarbose, a maltotetraose analog in which a maltose residue at the nonreducing end was replaced by acarviosine, was present, indicating that AmyB cleaves maltose units from the nonreducing end of maltooligosaccharides. These results indicate that AmyB is a new type exo-acting intracellular alpha-amylase possessing distinct characteristics that distinguish it from typical alpha-amylase and cyclodextrin-/pullulan-hydrolyzing enzymes.
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Affiliation(s)
- Kyung-Min Park
- Department of Microbiology, College of Natural Sciences, Pusan National University, San 30, Jangjeon-dong, Geumjeong-gu, Busan, 609-735, Korea
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Wang X, Feng Y, Wang H, Qu Y, Yu Y, Ren N, Li N, Wang E, Lee H, Logan BE. Bioaugmentation for electricity generation from corn stover biomass using microbial fuel cells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:6088-6093. [PMID: 19731723 DOI: 10.1021/es900391b] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Corn stover is usually treated by an energy-intensive or expensive process to extract sugars for bioenergy production. However, it is possible to directly generate electricity from corn stover in microbial fuel cells (MFCs) through the addition of microbial consortia specifically acclimated for biomass breakdown. A mixed culture that was developed to have a high saccharification rate with corn stover was added to single-chamber, air-cathode MFCs acclimated for power production using glucose. The MFC produced a maximum power of 331 mW/m2 with the bioaugmented mixed culture and corn stover, compared to 510 mW/m2 using glucose. Denaturing gradient gel electrophoresis (DGGE) showed the communities continued to evolve on both the anode and corn stover biomass over 60 days, with several bacteria identified including Rhodopseudomonas palustris. The use of residual solids from the steam exploded corn stover produced 8% more power (406 mW/m2) than the raw corn stover. These results show that it is possible to directly generate electricity from waste corn stover in MFCs through bioaugmentation using naturally occurring bacteria.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Urban Water Resource and Environment, No. 73 Huanghe Road, Nangang District, Harbin 150090, China
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Camassola M, De Bittencourt LR, Shenem NT, Andreaus J, Dillon AJP. Characterization of the Cellulase Complex ofPenicillium echinulatum. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420400024532] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Purification and characterization of an endoglucanase from Aspergillus terreus highly active against barley β-glucan and xyloglucan. World J Microbiol Biotechnol 2009. [DOI: 10.1007/s11274-009-0001-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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