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Haddad Momeni M, Zitting A, Jäämuru V, Turunen R, Penttilä P, Buchko GW, Hiltunen S, Maiorova N, Koivula A, Sapkota J, Marjamaa K, Master ER. Insights into the action of phylogenetically diverse microbial expansins on the structure of cellulose microfibrils. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:56. [PMID: 38654330 DOI: 10.1186/s13068-024-02500-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND Microbial expansins (EXLXs) are non-lytic proteins homologous to plant expansins involved in plant cell wall formation. Due to their non-lytic cell wall loosening properties and potential to disaggregate cellulosic structures, there is considerable interest in exploring the ability of microbial expansins (EXLX) to assist the processing of cellulosic biomass for broader biotechnological applications. Herein, EXLXs with different modular structure and from diverse phylogenetic origin were compared in terms of ability to bind cellulosic, xylosic, and chitinous substrates, to structurally modify cellulosic fibrils, and to boost enzymatic deconstruction of hardwood pulp. RESULTS Five heterogeneously produced EXLXs (Clavibacter michiganensis; CmiEXLX2, Dickeya aquatica; DaqEXLX1, Xanthomonas sacchari; XsaEXLX1, Nothophytophthora sp.; NspEXLX1 and Phytophthora cactorum; PcaEXLX1) were shown to bind xylan and hardwood pulp at pH 5.5 and CmiEXLX2 (harboring a family-2 carbohydrate-binding module) also bound well to crystalline cellulose. Small-angle X-ray scattering revealed a 20-25% increase in interfibrillar distance between neighboring cellulose microfibrils following treatment with CmiEXLX2, DaqEXLX1, or NspEXLX1. Correspondingly, combining xylanase with CmiEXLX2 and DaqEXLX1 increased product yield from hardwood pulp by ~ 25%, while supplementing the TrAA9A LPMO from Trichoderma reesei with CmiEXLX2, DaqEXLX1, and NspEXLX1 increased total product yield by over 35%. CONCLUSION This direct comparison of diverse EXLXs revealed consistent impacts on interfibrillar spacing of cellulose microfibers and performance of carbohydrate-active enzymes predicted to act on fiber surfaces. These findings uncover new possibilities to employ EXLXs in the creation of value-added materials from cellulosic biomass.
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Affiliation(s)
- Majid Haddad Momeni
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland.
| | - Aleksi Zitting
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland
| | - Vilma Jäämuru
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland
| | - Rosaliina Turunen
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland
| | - Paavo Penttilä
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland
| | - Garry W Buchko
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- School of Molecular Biosciences, Washington State University, Pullman, WA, 99164, USA
| | - Salla Hiltunen
- NE Research Center, UPM Pulp Research and Innovations, 53200, Lappeenranta, Finland
| | - Natalia Maiorova
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044-VTT, Espoo, Finland
| | - Anu Koivula
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044-VTT, Espoo, Finland
| | - Janak Sapkota
- NE Research Center, UPM Pulp Research and Innovations, 53200, Lappeenranta, Finland
| | - Kaisa Marjamaa
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044-VTT, Espoo, Finland
| | - Emma R Master
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland.
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada.
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2
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Su G, Lin Y, Wang C, Lu J, Liu Z, He Z, Shu X, Chen W, Wu R, Li B, Zhu C, Rose JKC, Grierson D, Giovannoni JJ, Shi Y, Chen K. Expansin SlExp1 and endoglucanase SlCel2 synergistically promote fruit softening and cell wall disassembly in tomato. THE PLANT CELL 2024; 36:709-726. [PMID: 38000892 PMCID: PMC10896287 DOI: 10.1093/plcell/koad291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/18/2023] [Accepted: 11/04/2023] [Indexed: 11/26/2023]
Abstract
Fruit softening, an irreversible process that occurs during fruit ripening, can lead to losses and waste during postharvest transportation and storage. Cell wall disassembly is the main factor leading to loss of fruit firmness, and several ripening-associated cell wall genes have been targeted for genetic modification, particularly pectin modifiers. However, individual knockdown of most cell wall-related genes has had minimal influence on cell wall integrity and fruit firmness, with the notable exception of pectate lyase. Compared to pectin disassembly, studies of the cell wall matrix, the xyloglucan-cellulose framework, and underlying mechanisms during fruit softening are limited. Here, a tomato (Solanum lycopersicum) fruit ripening-associated α-expansin (SlExpansin1/SlExp1) and an endoglucanase (SlCellulase2/SlCel2), which function in the cell wall matrix, were knocked out individually and together using clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9-mediated genome editing. Simultaneous knockout of SlExp1 and SlCel2 enhanced fruit firmness, reduced depolymerization of homogalacturonan-type pectin and xyloglucan, and increased cell adhesion. In contrast, single knockouts of either SlExp1 or SlCel2 did not substantially change fruit firmness, while simultaneous overexpression of SlExp1 and SlCel2 promoted early fruit softening. Collectively, our results demonstrate that SlExp1 and SlCel2 synergistically regulate cell wall disassembly and fruit softening in tomato.
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Affiliation(s)
- Guanqing Su
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Yifan Lin
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Chunfeng Wang
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Jiao Lu
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Zimeng Liu
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Zhiren He
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Xiu Shu
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Wenbo Chen
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Rongrong Wu
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Baijun Li
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Changqing Zhu
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Jocelyn K C Rose
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Donald Grierson
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - James J Giovannoni
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
- United States Department of Agriculture - Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853, USA
| | - Yanna Shi
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Kunsong Chen
- College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
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3
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Dahiya D, Koitto T, Kutvonen K, Wang Y, Haddad Momeni M, de Ruijter S, Master ER. Fungal loosenin-like proteins boost the cellulolytic enzyme conversion of pretreated wood fiber and cellulosic pulps. BIORESOURCE TECHNOLOGY 2024; 394:130188. [PMID: 38104665 DOI: 10.1016/j.biortech.2023.130188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023]
Abstract
Microbial expansin-related proteins, including loosenins, can disrupt cellulose networks and increase enzyme accessibility to cellulosic substrates. Herein, four loosenins from Phanerochaete carnosa (PcaLOOLs), and a PcaLOOL fused to a family 63 carbohydrate-binding module, were compared for ability to boost the cellulolytic deconstruction of steam pretreated softwood (SSW) and kraft pulps from softwood (ND-BSKP) and hardwood (ND-BHKP). Amending the Cellic® CTec-2 cellulase cocktail with PcaLOOLs increased reducing products from SSW by up to 40 %, corresponding to 28 % higher glucose yield. Amending Cellic® CTec-2 with PcaLOOLs also increased the release of glucose from ND-BSKP and ND-BHKP by 82 % and 28 %, respectively. Xylose release from ND-BSKP and ND-BHKP increased by 47 % and 57 %, respectively, highlighting the potential of PcaLOOLs to enhance hemicellulose recovery. Scanning electron microscopy and fiber image analysis revealed fibrillation and curlation of ND-BSKP after PcaLOOL treatment, consistent with increasing enzyme accessibility to targeted substrates.
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Affiliation(s)
- Deepika Dahiya
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Taru Koitto
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Kim Kutvonen
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Yan Wang
- Biorefining Business Development & Production, St1 Oy, Firdonkatu 2, 00520 Helsinki, Finland
| | - Majid Haddad Momeni
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Siiri de Ruijter
- Biorefining Business Development & Production, St1 Oy, Firdonkatu 2, 00520 Helsinki, Finland
| | - Emma R Master
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150 Espoo, Finland; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, M5S 3E5 Toronto, Ontario, Canada.
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4
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Sharker B, Islam MA, Hossain MAA, Ahmad I, Al Mamun A, Ghosh S, Rahman A, Hossain MS, Ashik MA, Hoque MR, Hossain MK, M Al Mamun, Haque MA, Patel H, Prodhan MY, Bhattacharya P, Haque MA. Characterization of lignin and hemicellulose degrading bacteria isolated from cow rumen and forest soil: Unveiling a novel enzymatic model for rice straw deconstruction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166704. [PMID: 37657552 DOI: 10.1016/j.scitotenv.2023.166704] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/03/2023]
Abstract
Application of greener pretreatment technology using robust ligninolytic bacteria for short duration to deconstruct rice straw and enhance bioethanol production is currently lacking. The objective of this study is to characterize three bacterial strains isolated from the milieux of cow rumen and forest soil and explore their capabilities of breaking down lignocellulose - an essential process in bioethanol production. Using biochemical and genomic analyses these strains were identified as Bacillus sp. HSTU-bmb18, Bacillus sp. HSTU-bmb19, and Citrobacter sp. HSTU-bmb20. Genomic analysis of the strains unveiled validated model hemicellulases, multicopper oxidases, and pectate lyases. These enzymes exhibited interactions with distinct lignocellulose substrates, further affirmed by their stability in molecular dynamic simulations. A comprehensive expression of ligninolytic pathways, including β-ketoadipate, phenyl acetate, and benzoate, was observed within the HSTU-bmb20 genome. The strains secreted approximately 75-82 U/mL of cellulase, xylase, pectinase, and lignin peroxidase. FT-IR analysis of the bacterial treated rice straw fibers revealed that the intensity of lignin-related peaks decreased, while cellulose-related peaks sharpened. The values of crystallinity index for the untreated control and the treated rice straw with either HSTU-bmb18, or HSTU-bmb19, or HSTU-bmb20 were recorded to be 34.48, 28.49, 29.36, 31.75, respectively, which are much higher than that of 13.53 noted for those treated with the bacterial consortium. The ratio of fermentable cellulose in rice straw increased by 1.25-, 1.79-, 1.93- and 2.17-fold following treatments with HSTU-bmb18, HSTU-bmb20, HSTU-bmb19, and a mixed consortium of these three strains, respectively. These aggregative results suggested a novel model for rice straw deconstruction utilizing hydrolytic enzymes of the consortium, revealing superior efficacy compared to individual strains, and advancing cost-effective, affordable, and sustainable green technology.
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Affiliation(s)
- Bishal Sharker
- Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh
| | - Md Aminul Islam
- Advanced Molecular Lab, Department of Microbiology, President Abdul Hamid Medical College, Karimganj-2310, Kishoreganj, Bangladesh; COVID-19 Diagnostic Lab, Department of Microbiology, Noakhali Science and Technology University, Noakhali 3814, Bangladesh
| | - Md Al Amin Hossain
- Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh
| | - Iqrar Ahmad
- Department of Pharmaceutical Chemistry, Prof. Ravindra Nikam College of Pharmacy, Gondur, Dhule, 424002, India
| | - Abdullah Al Mamun
- Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh
| | - Sibdas Ghosh
- Department of Biological Sciences, College of Arts and Sciences, Carlow University, 3333 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Aminur Rahman
- Department of Biomedical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Md Shohorab Hossain
- Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh; Department of Biochemistry and Molecular Biology, Trust University, Barishal, Bangladesh
| | - Md Ashikujjaman Ashik
- Department of Biochemistry and Molecular Biology, Trust University, Barishal, Bangladesh
| | - Md Rayhanul Hoque
- Department of Soil Science, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh
| | - Md Khalid Hossain
- Institute of Electronics, Atomic Energy Research Establishment, Bangladesh Atomic Energy Commission, Dhaka 1349, Bangladesh
| | - M Al Mamun
- Materials Science Division, Atomic Energy Centre Dhaka, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh
| | - Md Atiqul Haque
- Department of Microbiology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh; Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Harun Patel
- Division of Computer Aided Drug Design, Department of Pharmaceutical Chemistry, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
| | - Md Yeasin Prodhan
- Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh
| | - Prosun Bhattacharya
- COVID-19 Research, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE 10044 Stockholm, Sweden.
| | - Md Azizul Haque
- Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh.
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Li G, Yuan Y, Jin B, Zhang Z, Murtaza B, Zhao H, Li X, Wang L, Xu Y. Feasibility insights into the application of Paenibacillus pabuli E1 in animal feed to eliminate non-starch polysaccharides. Front Microbiol 2023; 14:1205767. [PMID: 37608941 PMCID: PMC10440823 DOI: 10.3389/fmicb.2023.1205767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/25/2023] [Indexed: 08/24/2023] Open
Abstract
The goal of the research was to find alternative protein sources for animal farming that are efficient and cost-effective. The researchers focused on distillers dried grains with solubles (DDGS), a co-product of bioethanol production that is rich in protein but limited in its use as a feed ingredient due to its high non-starch polysaccharides (NSPs) content, particularly for monogastric animals. The analysis of the Paenibacillus pabuli E1 genome revealed the presence of 372 genes related to Carbohydrate-Active enzymes (CAZymes), with 98 of them associated with NSPs degrading enzymes that target cellulose, hemicellulose, and pectin. Additionally, although lignin is not an NSP, two lignin-degrading enzymes were also examined because the presence of lignin alongside NSPs can hinder the catalytic effect of enzymes on NSPs. To confirm the catalytic ability of the degrading enzymes, an in vitro enzyme activity assay was conducted. The results demonstrated that the endoglucanase activity reached 5.37 U/mL, while beta-glucosidase activity was 4.60 U/mL. The filter paper experiments did not detect any reducing sugars. The xylanase and beta-xylosidase activities were measured at 11.05 and 4.16 U/mL, respectively. Furthermore, the pectate lyase and pectin lyase activities were found to be 8.19 and 2.43 U/mL, respectively. The activities of laccase and MnP were determined as 1.87 and 4.30 U/mL, respectively. The researchers also investigated the effect of P. pabuli E1 on the degradation of NSPs through the solid-state fermentation of DDGS. After 240 h of fermentation, the results showed degradation rates of 11.86% for hemicellulose, 11.53% for cellulose, and 8.78% for lignin. Moreover, the crude protein (CP) content of DDGS increased from 26.59% to 30.59%. In conclusion, this study demonstrated that P. pabuli E1 possesses various potential NSPs degrading enzymes that can effectively eliminate NSPs in feed. This process improves the quality and availability of the feed, which is important for animal farming as it seeks alternative protein sources to replace traditional nutrients.
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Affiliation(s)
- Gen Li
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Yue Yuan
- School of Biological Engineering, Dalian Polytechnic University, Dalian, China
| | - Bowen Jin
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Zhiqiang Zhang
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Bilal Murtaza
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Hong Zhao
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Xiaoyu Li
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Lili Wang
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Yongping Xu
- School of Bioengineering, Dalian University of Technology, Dalian, China
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6
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Zhou R, Zhang L, Zeng B, Zhou Y, Jin W, Zhang G. A novel self-purified auxiliary protein enhances the lichenase activity towards lichenan for biomass degradation. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12608-y. [PMID: 37272940 DOI: 10.1007/s00253-023-12608-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/06/2023]
Abstract
Due to the complex composition of lichenan, lichenase alone cannot always hydrolyze it efficiently. Carbohydrate-binding modules (CBMs) and lytic polysaccharide monooxygenases (LPMOs) have been confirmed to increase the hydrolysis efficiency of lichenases. However, their practical application was hampered by the complex and costly preparation procedure, as well as the poor stability of LPMOs. Herein, we discovered a novel and stable auxiliary protein named SCE to boost the hydrolysis efficiency. SCE was composed of SpyCatcher (SC) and elastin-like polypeptides (ELPs) and could be easily and cheaply prepared. Under the optimal conditions, the boosting degree for SCE/lichenase was 1.45, and the reducing sugar yield improved by nearly 45%. The results of high-performance liquid chromatography (HPLC) indicated that SCE had no influence on the hydrolysis pattern of lichenase. Through the experimental verification and bioinformatics analysis, we proposed the role of SCE in promoting the interaction between the lichenase and substrates. These findings endow SC with a novel function in binding to insoluble lichenan, paving the way for biomass degradation and biorefinery. KEY POINTS: • A novel self-purification auxiliary protein that could boost the hydrolysis efficiency of lichenase has been identified. • The protein is highly produced, simple to prepare, well stable, and does not require any external electron donor. • The novel function of SpyCatcher in binding to insoluble lichenan was first demonstrated.
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Affiliation(s)
- Rui Zhou
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Lingzhi Zhang
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Bo Zeng
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Yanhong Zhou
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Wenhui Jin
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, Fujian Province, People's Republic of China
| | - Guangya Zhang
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China.
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7
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Xu C, Xia T, Peng H, Liu P, Wang Y, Wang Y, Kang H, Tang J, Nauman Aftab M, Peng L. BsEXLX of engineered Trichoderma reesei strain as dual-active expansin to boost cellulases secretion for synergistic enhancement of biomass enzymatic saccharification in corn and Miscanthus straws. BIORESOURCE TECHNOLOGY 2023; 376:128844. [PMID: 36906237 DOI: 10.1016/j.biortech.2023.128844] [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: 01/31/2023] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
In this study, bacterial BsEXLE1 gene was overexpressed into T. reesei (Rut-C30) to generate a desirable engineered TrEXLX10 strain. While incubated with alkali-pretreated Miscanthus straw as carbon source, the TrEXLX10 secreted the β-glucosidases, cellobiohydrolases and xylanses with activities raised by 34%, 82% and 159% compared to the Rut-C30. Supplying EXLX10-secreted crude enzymes and commercial mixed-cellulases for two-step lignocellulose hydrolyses of corn and Miscanthus straws after mild alkali pretreatments, this work measured consistently higher hexoses yields released by the EXLX10-secreted enzymes for synergistic enhancements of biomass saccharification in all parallel experiments examined. Meanwhile, this study detected that the expansin, purified from EXLX10-secreted solution, was of exceptionally high binding activities with wall polymers, and further determined its independent enhancement for cellulose hydrolysis. Therefore, this study raised a mechanism model to highlight EXLX/expansin dual-activation roles for both secretion of stable biomass-degradation enzymes at high activity and biomass enzymatic saccharification in bioenergy crops.
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Affiliation(s)
- Chengbao Xu
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China; Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China; School of Basic Medical Sciences, Hubei University of Medicine, Shiyan 442000, China
| | - Tao Xia
- Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China; College of Life Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Hao Peng
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China; Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Peng Liu
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China; Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yihong Wang
- Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yanting Wang
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China; Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Heng Kang
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China; Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Jingfeng Tang
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China
| | | | - Liangcai Peng
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation & Molecular Pharmaceutics, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, College of Biotechnology & Food Science, Hubei University of Technology, Wuhan 430068, China; Biomass & Bioenergy Research Centre, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, China.
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8
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Laemthong T, Bing RG, Crosby JR, Manesh MJH, Adams MWW, Kelly RM. Role of cell-substrate association during plant biomass solubilization by the extreme thermophile Caldicellulosiruptor bescii. Extremophiles 2023; 27:6. [PMID: 36802247 PMCID: PMC10514702 DOI: 10.1007/s00792-023-01290-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/02/2023] [Indexed: 02/23/2023]
Abstract
Caldicellulosiruptor species are proficient at solubilizing carbohydrates in lignocellulosic biomass through surface (S)-layer bound and secretomic glycoside hydrolases. Tāpirins, surface-associated, non-catalytic binding proteins in Caldicellulosiruptor species, bind tightly to microcrystalline cellulose, and likely play a key role in natural environments for scavenging scarce carbohydrates in hot springs. However, the question arises: If tāpirin concentration on Caldicellulosiruptor cell walls increased above native levels, would this offer any benefit to lignocellulose carbohydrate hydrolysis and, hence, biomass solubilization? This question was addressed by engineering the genes for tight-binding, non-native tāpirins into C. bescii. The engineered C. bescii strains bound more tightly to microcrystalline cellulose (Avicel) and biomass compared to the parent. However, tāpirin overexpression did not significantly improve solubilization or conversion for wheat straw or sugarcane bagasse. When incubated with poplar, the tāpirin-engineered strains increased solubilization by 10% compared to the parent, and corresponding acetate production, a measure of carbohydrate fermentation intensity, was 28% higher for the Calkr_0826 expression strain and 18.5% higher for the Calhy_0908 expression strain. These results show that enhanced binding to the substrate, beyond the native capability, did not improve C. bescii solubilization of plant biomass, but in some cases may improve conversion of released lignocellulose carbohydrates to fermentation products.
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Affiliation(s)
- Tunyaboon Laemthong
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
- Department of Chemical Engineering, Thammasat University, Pathum Thani, 12120, Thailand
| | - Ryan G Bing
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - James R Crosby
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Mohamad J H Manesh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Robert M Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA.
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9
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Monschein M, Jurak E, Paasela T, Koitto T, Lambauer V, Pavicic M, Enjalbert T, Dumon C, Master ER. PACER: a novel 3D plant cell wall model for the analysis of non-catalytic and enzymatic responses. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:30. [PMID: 35296345 PMCID: PMC8928621 DOI: 10.1186/s13068-022-02128-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/05/2022] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Substrate accessibility remains a key limitation to the efficient enzymatic deconstruction of lignocellulosic biomass. Limited substrate accessibility is often addressed by increasing enzyme loading, which increases process and product costs. Alternatively, considerable efforts are underway world-wide to identify amorphogenesis-inducing proteins and protein domains that increase the accessibility of carbohydrate-active enzymes to targeted lignocellulose components.
Results
We established a three-dimensional assay, PACER (plant cell wall model for the analysis of non-catalytic and enzymatic responses), that enables analysis of enzyme migration through defined lignocellulose composites. A cellulose/azo-xylan composite was made to demonstrate the PACER concept and then used to test the migration and activity of multiple xylanolytic enzymes. In addition to non-catalytic domains of xylanases, the potential of loosenin-like proteins to boost xylanase migration through cellulose/azo-xylan composites was observed.
Conclusions
The PACER assay is inexpensive and parallelizable, suitable for screening proteins for ability to increase enzyme accessibility to lignocellulose substrates. Using the PACER assay, we visualized the impact of xylan-binding modules and loosenin-like proteins on xylanase mobility and access to targeted substrates. Given the flexibility to use different composite materials, the PACER assay presents a versatile platform to study impacts of lignocellulose components on enzyme access to targeted substrates.
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10
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Madadi M, Song G, Sun F, Sun C, Xia C, Zhang E, Karimi K, Tu M. Positive role of non-catalytic proteins on mitigating inhibitory effects of lignin and enhancing cellulase activity in enzymatic hydrolysis: Application, mechanism, and prospective. ENVIRONMENTAL RESEARCH 2022; 215:114291. [PMID: 36103929 DOI: 10.1016/j.envres.2022.114291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/18/2022] [Accepted: 09/04/2022] [Indexed: 06/15/2023]
Abstract
Fermentable sugar production from lignocellulosic biomass has received considerable attention and has been dramatic progress recently. However, due to low enzymatic hydrolysis (EH) yields and rates, a high dosage of the costly enzyme is required, which is a bottleneck for commercial applications. Over the last decades, various strategies have been developed to reduce cellulase enzyme costs. The progress of the non-catalytic additive proteins in mitigating inhibition in EH is discussed in detail in this review. The low efficiency of EH is mostly due to soluble lignin compounds, insoluble lignin, and harsh thermal and mechanical conditions of the EH process. Adding non-catalytic proteins into the EH is considered a simple and efficient approach to boost hydrolysis yield. This review discussed the multiple mechanical steps involved in the EH process. The effect of physicochemical properties of modified lignin on EH and its interaction with cellulase and cellulose are identified and discussed, which include hydrogen bonding, hydrophobic, electrostatic, and cation-π interactions, as well as physical barriers. Moreover, the effects of different conditions of EH that lead to cellulase deactivation by thermal and mechanical mechanisms are also explained. Finally, recent advances in the development, potential mechanisms, and economic feasibility of non-catalytic proteins on EH are evaluated and perspectives are presented.
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Affiliation(s)
- Meysam Madadi
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Guojie Song
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
| | - Chihe Sun
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Changlei Xia
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China
| | - Ezhen Zhang
- Institute of Agro-Products Processing Science and Technology, Guangxi Academy of Agricultural Sciences, Nanning, 530007, China
| | - Keikhosro Karimi
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Maobing Tu
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, 45221, United States
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11
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Jia H, Feng X, Huang J, Guo Y, Zhang D, Li X, Zhao J. Recombinant Family 1 Carbohydrate-Binding Modules Derived From Fungal Cellulase Enhance Enzymatic Degradation of Lignocellulose as Novel Effective Accessory Protein. Front Microbiol 2022; 13:876466. [PMID: 35898911 PMCID: PMC9309510 DOI: 10.3389/fmicb.2022.876466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/09/2022] [Indexed: 11/23/2022] Open
Abstract
Fungal cellulases usually contain a family 1 carbohydrate-binding module (CBM1), and its role was considered to recognize the substrate specifically. This study testified that the CBM1s derived from cellobiohydrolase I of Trichoderma reesei, Penicillium oxalicum, and Penicillium funiculosum could be used as an effective accessory protein in cellulase cocktails to enhance the saccharification of lignocellulose, and its enhancement effect was significantly superior to some reported accessory proteins, such as bovine serum albumin (BSA). The promoting effects of the CBM1s were related to not only the CBM1 sources and protein dosages, but also the substrate characteristics and solid consistency during enzymatic hydrolysis. The adsorption capacity of the CBM1s, the adsorption kinetic of TrCBM from T. reesei and cellobiohydrolase, endoglucanase, and β-glucosidase from P. oxalicum, and the effect of adding TrCBM on enzyme activities of free cellulases in the hydrolysis system were investigated, and the binding conformations and affinities of CBM1s to cellulose and lignin were predicted by molecular docking. It was speculated that the higher affinity of the CBM1s to lignin than cellulases could potentially enable the CBM1s to displace cellulase adsorbed on lignin or to preferentially adsorb onto lignin to avoid ineffective adsorption of cellulase onto lignin, which enhanced cellulase system efficiency during enzymatic hydrolysis of lignocellulose.
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Affiliation(s)
- Hexue Jia
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiaoting Feng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jiamin Huang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yingjie Guo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Daolei Zhang
- School of Bioengineering, Shandong Polytechnic, Jinan, China
| | - Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
- *Correspondence: Xuezhi Li,
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
- Jian Zhao,
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12
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de Sandozequi A, Salazar-Cortés JJ, Tapia-Vázquez I, Martínez-Anaya C. Prevalent association with the bacterial cell envelope of prokaryotic expansins revealed by bioinformatics analysis. Protein Sci 2022; 31:e4315. [PMID: 35481628 PMCID: PMC9045087 DOI: 10.1002/pro.4315] [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: 12/20/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 11/10/2022]
Abstract
Expansins are a group of proteins from diverse organisms from bacteria to plants. Although expansins show structural conservation, their biological roles seem to differ among kingdoms. In plants, these proteins remodel the cell wall during plant growth and other processes. Contrarily, determination of bacterial expansin activity has proven difficult, although genetic evidence of bacterial mutants indicates that expansins participate in bacteria-plant interactions. Nevertheless, a large proportion of expansin genes are found in the genomes of free-living bacteria, suggesting roles that are independent of the interaction with living plants. Here, we analyzed all available sequences of prokaryotic expansins for correlations between surface electric charge, extra protein modules, and sequence motifs for association with the bacteria exterior after export. Additionally, information on the fate of protein after translocation across the membrane also points to bacterial cell association of expansins through six different mechanisms, such as attachment of a lipid molecule for membrane anchoring in diderm species or covalent linking to the peptidoglycan layer in monoderms such as the Bacilliales. Our results have implications for expansin function in the context of bacteria-plant interactions and also for free-living species in which expansins might affect cell-cell or cell-substrate interaction properties and indicate the need to re-examine the roles currently considered for these proteins.
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Affiliation(s)
- Andrés de Sandozequi
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
| | - Juan José Salazar-Cortés
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
| | - Irán Tapia-Vázquez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
| | - Claudia Martínez-Anaya
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
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13
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Luo T, Xu Q, Wei W, Sun J, Dai X, Ni BJ. Performance and Mechanism of Fe 3O 4 Improving Biotransformation of Waste Activated Sludge into Liquid High-Value Products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3658-3668. [PMID: 35254057 DOI: 10.1021/acs.est.1c05960] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This study demonstrated that Fe3O4 simultaneously improves the total production and formation rate of medium-chain fatty acids (MCFAs) and long-chain alcohols (LCAs) from waste activated sludge (WAS) in anaerobic fermentation. Results revealed that when Fe3O4 increased from 0 to 5 g/L, the maximal MCFA and LCA production increased significantly, and the optimal fermentation time was also remarkably shortened from 24 to 9 days. Moreover, Fe3O4 also enhanced WAS degradation, and the corresponding degradation rate in the fermentation system increased from 43.86 to 72.38% with an increase in Fe3O4 from 0 to 5 g/L. Further analysis showed that Fe3O4 promoted the microbe activities of all the bioprocesses (including hydrolysis, acidogenesis, and chain elongation processes) involved in the MCFA and LCA production from WAS. Microbial community analysis indicated that Fe3O4 increased the abundances of key microbes involved in abovementioned bioprocesses correspondingly. Mechanistic investigations showed that Fe3O4 increased the conductivity of the fermented sludge, providing a better conductive environment for the anaerobic microbes. The redox cycle of Fe(II) and Fe(III) existed in the fermentation system with Fe3O4, which was likely to act as electron shuttles to conduct electron transfer (ET) from the electron donor to the acceptor, thus increasing ET efficiency. This study provides an effective method for enhancing the biotransformation of WAS into high-value products, potentially bringing economic benefits to WAS treatment.
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Affiliation(s)
- Tianyi Luo
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Qiuxiang Xu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Wei Wei
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Jing Sun
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, New South Wales 2007, Australia
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14
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Samalova M, Gahurova E, Hejatko J. Expansin-mediated developmental and adaptive responses: A matter of cell wall biomechanics? QUANTITATIVE PLANT BIOLOGY 2022; 3:e11. [PMID: 37077967 PMCID: PMC10095946 DOI: 10.1017/qpb.2022.6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 03/16/2022] [Accepted: 03/29/2022] [Indexed: 05/03/2023]
Abstract
Biomechanical properties of the cell wall (CW) are important for many developmental and adaptive responses in plants. Expansins were shown to mediate pH-dependent CW enlargement via a process called CW loosening. Here, we provide a brief overview of expansin occurrence in plant and non-plant species, their structure and mode of action including the role of hormone-regulated CW acidification in the control of expansin activity. We depict the historical as well as recent CW models, discuss the role of expansins in the CW biomechanics and address the developmental importance of expansin-regulated CW loosening in cell elongation and new primordia formation. We summarise the data published so far on the role of expansins in the abiotic stress response as well as the rather scarce evidence and hypotheses on the possible mechanisms underlying expansin-mediated abiotic stress resistance. Finally, we wrap it up by highlighting possible future directions in expansin research.
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Affiliation(s)
- Marketa Samalova
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Evelina Gahurova
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biotechnological Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jan Hejatko
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biotechnological Research, Faculty of Science, Masaryk University, Brno, Czech Republic
- Author for correspondence: J. Hejatko, E-mail:
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15
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Defining the Frontiers of Synergism between Cellulolytic Enzymes for Improved Hydrolysis of Lignocellulosic Feedstocks. Catalysts 2021. [DOI: 10.3390/catal11111343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lignocellulose has economic potential as a bio-resource for the production of value-added products (VAPs) and biofuels. The commercialization of biofuels and VAPs requires efficient enzyme cocktail activities that can lower their costs. However, the basis of the synergism between enzymes that compose cellulolytic enzyme cocktails for depolymerizing lignocellulose is not understood. This review aims to address the degree of synergism (DS) thresholds between the cellulolytic enzymes and how this can be used in the formulation of effective cellulolytic enzyme cocktails. DS is a powerful tool that distinguishes between enzymes’ synergism and anti-synergism during the hydrolysis of biomass. It has been established that cellulases, or cellulases and lytic polysaccharide monooxygenases (LPMOs), always synergize during cellulose hydrolysis. However, recent evidence suggests that this is not always the case, as synergism depends on the specific mechanism of action of each enzyme in the combination. Additionally, expansins, nonenzymatic proteins responsible for loosening cell wall fibers, seem to also synergize with cellulases during biomass depolymerization. This review highlighted the following four key factors linked to DS: (1) a DS threshold at which the enzymes synergize and produce a higher product yield than their theoretical sum, (2) a DS threshold at which the enzymes display synergism, but not a higher product yield, (3) a DS threshold at which enzymes do not synergize, and (4) a DS threshold that displays anti-synergy. This review deconvolutes the DS concept for cellulolytic enzymes, to postulate an experimental design approach for achieving higher synergism and cellulose conversion yields.
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16
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Li R, Sun Y, Zhou Y, Gai J, You L, Yang F, Tang W, Li X. A novel decrystallizing protein CxEXL22 from Arthrobotrys sp. CX1 capable of synergistically hydrolyzing cellulose with cellulases. BIORESOUR BIOPROCESS 2021; 8:90. [PMID: 38650251 PMCID: PMC10992334 DOI: 10.1186/s40643-021-00446-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/16/2021] [Indexed: 11/10/2022] Open
Abstract
A novel expansin-like protein (CxEXL22) has been identified and characterized from newly isolated Arthrobotrys sp. CX1 that can cause cellulose decrystallization. Unlike previously reported expansin-like proteins from microbes, CxEXL22 has a parallel β-sheet domain at the N terminal, containing many hydrophobic residues to form the hydrophobic surface as part of the groove. The direct phylogenetic relationship implied the genetic transfers occurred from nematode to nematicidal fungal Arthrobotrys sp. CX1. CxEXL22 showed strong activity for the hydrolysis of hydrogen bonds between cellulose molecules, especially when highly crystalline cellulose was used as substrate. The hydrolysis efficiency of Avicel was increased 7.9-fold after pretreating with CxEXL22. The rupture characterization of crystalline region indicated that CxEXL22 strongly binds cellulose and breaks up hydrogen bonds in the crystalline regions of cellulose to split cellulose chains, causing significant depolymerization to expose much more microfibrils and enhances cellulose accessibility.
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Affiliation(s)
- Rong Li
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Yunze Sun
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Yihao Zhou
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Jiawei Gai
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Linlu You
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Fan Yang
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Wenzhu Tang
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China
| | - Xianzhen Li
- School of Biological Engineering, Dalian Polytechnic University, Gangjingqu, Dalian, 116034, China.
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Isolation and Purification of a New Bacillus Subtilis Strain from Deer Dung with Anti-microbial and Anti-cancer Activities. Curr Med Sci 2021; 41:832-840. [PMID: 34403110 DOI: 10.1007/s11596-021-2383-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 01/29/2021] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Bacillus strains are well known for their natural bioactive products that have antimicrobial and/or anti-cancer activities. Many of Bacillus' structurally unique metabolites can combat human diseases, including cancers. However, because Bacillus' metabolites are so abundant, few have been studied extensively enough to fully characterize their chemical constitutions and biological functions. METHODS In this study, we focused on the isolation and purification of a new Bacillus strain, and determined the effects of its metabolites on bacteria and cancer cells. Our study focused on a new strain of Bacillus isolated from deer dung. Based on BLAST results, this isolate belongs to Bacillus subtilis, and therefore we named the strain Bacillus subtilis NC16. Congo red assay was used to test the cellulase activity. The inhibition zone was measured to test the antimicrobial activity. CCK-8, wound healing and flow cytometry were used to test the anti-cancer activity. RESULTS Metabolites from Bacillus subtilis NC16 have both antimicrobial and anti-cancer activities. They can both suppress the growth of Trichoderma vride and Staphylococcus aureus, and inhibit the proliferation and promote the apoptosis of non-small cell lung cancer cell lines. CONCLUSION Our results suggest that Bacillus subtilis NC16 can not only degrade cellulose, but its metabolites may be sources of antibiotics and anti-cancer drugs.
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Zhang P, Cui M, Huang R, Qi W, Thielemans W, He Z, Su R. Enhanced enzymatic hydrolysis of cellulose by endoglucanase via expansin pretreatment and the addition of zinc ions. BIORESOURCE TECHNOLOGY 2021; 333:125139. [PMID: 33882384 DOI: 10.1016/j.biortech.2021.125139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
One of the major limitations of lignocellulose conversion is the relatively low efficiency of cellulases. Expansins can act as an accessory protein to loosen the rigid cellulose structure and promote cellulose hydrolysis. However, the synergistic action of expansin is not well understood. In this study, we employed quartz crystal microbalance with dissipation to real-time monitor the adsorption of Bacillus subtilis expansin (BsEXLX1) and endoglucanase I (Cel7B) and the hydrolysis of cellulose. The effects of pH, temperature, and zinc ions on the initial adsorption rate and adsorption capacity of BsEXLX1 were examined. When 36.5 mM of zinc ions was added, the irreversible adsorption ratio of BsEXLX1 further increased to 4.63 times the value in the absence of zinc ions, whereas the initial adsorption rate and the hydrolysis rate constants of Cel7B could reach 2.16 times and 2.05 times the values in the absence of zinc ions, respectively.
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Affiliation(s)
- Peiqian Zhang
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
| | - Mei Cui
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Renliang Huang
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Wei Qi
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China
| | - Wim Thielemans
- Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
| | - Zhimin He
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Rongxin Su
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; School of Marine Science and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China.
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19
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Zhang P, Su R, Duan Y, Cui M, Huang R, Qi W, He Z, Thielemans W. Synergy between endo/exo-glucanases and expansin enhances enzyme adsorption and cellulose conversion. Carbohydr Polym 2021; 253:117287. [DOI: 10.1016/j.carbpol.2020.117287] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 10/01/2020] [Accepted: 10/17/2020] [Indexed: 10/23/2022]
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20
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Cui M, Duan Y, Ma Y, Al-Shwafy KWA, Liu Y, Zhao X, Huang R, Qi W, He Z, Su R. Real-Time QCM-D Monitoring of the Adsorption-Desorption of Expansin on Lignin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4503-4510. [PMID: 32241112 DOI: 10.1021/acs.langmuir.0c00104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Expansin has nonhydrolytic disruptive activity and synergistically acts with cellulases to enhance the hydrolysis of cellulose. The adsorption-desorption of expansin on noncellulosic lignin can greatly affect the action of expansin on lignocellulose. In this study, three lignins with different sources (kraft lignin (KL), sodium lignin sulfonate (SLS), and enzymatic hydrolysis lignin (EHL)) were selected as the substrates. The real-time adsorption-desorption of Bacillus subtilis expansin (BsEXLX1) on lignins was monitored using quartz crystal microgravimetry with dissipation (QCM-D). The effects of temperature and Tween 80 on the adsorption-desorption behaviors were also investigated. The results show that BsEXLX1 exhibited high binding ability on lignin and achieved maximum adsorption of 283.2, 273.8, and 266.9 ng cm-2 at 25 °C on KL, SLS, and EHL, respectively. The maximum adsorption decreased to 148.2-192.8 ng cm-2 when the temperature increased from 25 to 45 °C. Moreover, Tween 80 competitively bound to lignin and significantly prevented expansin adsorption. After irreversible adsorption of Tween 80, the maximum adsorption of BsEXLX1 greatly decreased to 33.3, 37.2, and 10.3 ng cm-2 at 25 °C on KL, SLS, and EHL, respectively. Finally, a kinetic model was developed to analyze the adsorption-desorption process of BsEXLX1. BsEXLX1 has a higher adsorption rate constant (kA) and a lower desorption rate constant (kD) on KL than on SLS and EHL. The findings of this study provide useful insights into the adsorption-desorption of expansin on lignin.
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Affiliation(s)
- Mei Cui
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yuhao Duan
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yuanyuan Ma
- Biomass Conversion Laboratory of Tianjin University R&D Center for Petrochemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Khaled W A Al-Shwafy
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yudong Liu
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Xudong Zhao
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Renliang Huang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Wei Qi
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Zhimin He
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Rongxin Su
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, China
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21
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Zhang P, Ma Y, Cui M, Wang J, Huang R, Su R, Qi W, He Z, Thielemans W. Effect of Sugars on the Real-Time Adsorption of Expansin on Cellulose. Biomacromolecules 2020; 21:1776-1784. [DOI: 10.1021/acs.biomac.9b01694] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peiqian Zhang
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
- Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
| | - Yuanyuan Ma
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Mei Cui
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Jieying Wang
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Renliang Huang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, P.R. China
| | - Rongxin Su
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Wei Qi
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China
| | - Zhimin He
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Wim Thielemans
- Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
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An expansin-like protein expands forage cell walls and synergistically increases hydrolysis, digestibility and fermentation of livestock feeds by fibrolytic enzymes. PLoS One 2019; 14:e0224381. [PMID: 31689330 PMCID: PMC6830940 DOI: 10.1371/journal.pone.0224381] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 10/12/2019] [Indexed: 11/19/2022] Open
Abstract
Bacterial expansin-like proteins have synergistically increased cellulose hydrolysis by cellulolytic enzymes during the initial stages of biofuel production, but they have not been tested on livestock feeds. The objectives of this study were to: isolate and express an expansin-like protein (BsEXLX1), to verify its disruptive activity (expansion) on cotton fibers by immunodetection (Experiment 1), and to determine the effect of dose, pH and temperature for BsEXLX1 and cellulase to synergistically hydrolyze filter paper (FP) and carboxymethyl cellulose (CMC) under laboratory (Experiment 2) and simulated ruminal (Experiment 3) conditions. In addition, we determined the ability of BsEXLX1 to synergistically increase hydrolysis of corn and bermudagrass silages by an exogenous fibrolytic enzyme (EFE) (Experiment 4) and how different doses of BsEXLX1 and EFE affect the gas production (GP), in vitro digestibility and fermentation of a diet for dairy cows (Experiment 5). In Experiment 1, immunofluorescence-based examination of cotton microfiber treated without or with recombinant expansin-like protein expressed from Bacillus subtilis (BsEXLX1) increased the surface area by > 100% compared to the untreated control. In Experiment 2, adding BsEXLX1 (100 μg/g FP) to cellulase (0.0148 FPU) increased release of reducing sugars compared to cellulase alone by more than 40% (P < 0.01) at optimal pH (4.0) and temperature (50°C) after 24 h. In Experiment 3 and 4, adding BsEXLX1 to cellulase or EFE, synergistically increased release of reducing sugars from FP, corn and bermudagrass silages under simulated ruminal conditions (pH 6.0, 39°C). In Experiment 5, increasing the concentration of BsEXLX1 linearly increased (P < 0.01) GP from fermentation of a diet for dairy cows by up to 17.8%. Synergistic effects between BsEXLX1 and EFE increased in vitro NDF digestibility of the diet by 23.3% compared to the control. In vitro digestibility of hemicellulose and butyrate concentration were linearly increased by BsEXLX1 compared to the control. This study demonstrated that BsEXLX1 can improve the efficacy of cellulase and EFE at hydrolyzing pure substrates and dairy cow feeds, respectively.
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Adsul M, Sandhu SK, Singhania RR, Gupta R, Puri SK, Mathur A. Designing a cellulolytic enzyme cocktail for the efficient and economical conversion of lignocellulosic biomass to biofuels. Enzyme Microb Technol 2019; 133:109442. [PMID: 31874688 DOI: 10.1016/j.enzmictec.2019.109442] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 11/19/2022]
Abstract
Concerns about dwindling fossil fuels and their unfavorable environmental impacts shifted the global focus towards the development of biofuels from lignocellulosic feedstocks. The structure of this biomass is very complex due to which variety of enzymes (cellulolytic, hemicellulolytic, auxiliary/AA9) and proteins (e.g. swollenin) required for efficient deconstruction. Major impediments in large-scale commercial production of cellulosic ethanol are the cost of cellulases and inability of any single microorganism to produce all cellulolytic components in sufficient titers. In the recent past, various methods for reducing the enzyme cost during cellulosic ethanol production have been attempted. These include designing optimal synergistic enzyme blends/cocktail, having certain ratios of enzymes from different microbial sources, for efficient hydrolysis of pretreated biomass. However, the mechanisms underlying the development, strategies for production and evaluation of optimal cellulolytic cocktails still remain unclear. This article aims to explore the technical and economic benefits of using cellulolytic enzyme cocktail, basic enzymatic and non-enzymatic components required for its development and various strategies employed for efficient cellulolytic cocktail preparation. Consideration was also given to the ways of evaluation of commercially available and in-house developed cocktails. Discussion about commercially available cellulolytic cocktails, current challenges and possible avenues in the development of cellulolytic cocktails included.
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Affiliation(s)
- Mukund Adsul
- DBT-IOC Centre for Advanced Bioenergy Research, R & D Centre, Indian Oil Corporation Ltd, Sector-13, Faridabad 121007, India.
| | - Simranjeet Kaur Sandhu
- DBT-IOC Centre for Advanced Bioenergy Research, R & D Centre, Indian Oil Corporation Ltd, Sector-13, Faridabad 121007, India
| | - Reeta Rani Singhania
- DBT-IOC Centre for Advanced Bioenergy Research, R & D Centre, Indian Oil Corporation Ltd, Sector-13, Faridabad 121007, India
| | - Ravi Gupta
- DBT-IOC Centre for Advanced Bioenergy Research, R & D Centre, Indian Oil Corporation Ltd, Sector-13, Faridabad 121007, India
| | - Suresh K Puri
- DBT-IOC Centre for Advanced Bioenergy Research, R & D Centre, Indian Oil Corporation Ltd, Sector-13, Faridabad 121007, India
| | - Anshu Mathur
- DBT-IOC Centre for Advanced Bioenergy Research, R & D Centre, Indian Oil Corporation Ltd, Sector-13, Faridabad 121007, India
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High-Level Abundances of Methanobacteriales and Syntrophobacterales May Help To Prevent Corrosion of Metal Sheet Piles. Appl Environ Microbiol 2019; 85:AEM.01369-19. [PMID: 31420342 DOI: 10.1128/aem.01369-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/11/2019] [Indexed: 11/20/2022] Open
Abstract
Iron sheet piles are widely used in flood protection, dike construction, and river bank reinforcement. Their corrosion leads to gradual deterioration and often makes replacement necessary. Natural deposit layers on these sheet piles can prevent degradation and significantly increase their life span. However, little is known about the mechanisms of natural protective layer formation. Here, we studied the microbially diverse populations of corrosion-protective deposit layers on iron sheet piles at the Gouderak pumping station in Zuid-Holland, the Netherlands. Deposit layers, surrounding sediment and top sediment samples were analyzed for soil physicochemical parameters, microbially diverse populations, and metabolic potential. Methanogens appeared to be enriched 18-fold in the deposit layers. After sequencing, metagenome assembly and binning, we obtained four nearly complete draft genomes of microorganisms (Methanobacteriales, two Coriobacteriales, and Syntrophobacterales) that were highly enriched in the deposit layers, strongly indicating a potential role in corrosion protection. Coriobacteriales and Syntrophobacterales could be part of a microbial food web degrading organic matter to supply methanogenic substrates. Methane-producing Methanobacteriales could metabolize iron, which may initially lead to mild corrosion but potentially stimulates the formation of a carbonate-rich protective deposit layer in the long term. In addition, Methanobacteriales and Coriobacteriales have the potential to interact with metal surfaces via direct interspecies or extracellular electron transfer. In conclusion, our study provides valuable insights into microbial populations involved in iron corrosion protection and potentially enables the development of novel strategies for in situ screening of iron sheet piles in order to reduce risks and develop more sustainable replacement practices.IMPORTANCE Iron sheet piles are widely used to reinforce dikes and river banks. Damage due to iron corrosion poses a significant safety risk and has significant economic impact. Different groups of microorganisms are known to either stimulate or inhibit the corrosion process. Recently, natural corrosion-protective deposit layers were found on sheet piles. Analyses of the microbial composition indicated a potential role for methane-producing archaea. However, the full metabolic potential of the microbial communities within these protective layers has not been determined. The significance of this work lies in the reconstruction of the microbial food web of natural corrosion-protective layers isolated from noncorroding metal sheet piles. With this work, we provide insights into the microbiological mechanisms that potentially promote corrosion protection in freshwater ecosystems. Our findings could support the development of screening protocols to assess the integrity of iron sheet piles to decide whether replacement is required.
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Hepler NK, Cosgrove DJ. Directed
in vitro
evolution of bacterial expansin BsEXLX1 for higher cellulose binding and its consequences for plant cell wall‐loosening activities. FEBS Lett 2019; 593:2545-2555. [DOI: 10.1002/1873-3468.13528] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/28/2019] [Accepted: 07/02/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Nathan K. Hepler
- Huck Institutes of the Life Sciences The Pennsylvania State University University Park PA USA
- Department of Biology The Pennsylvania State University University Park PA USA
| | - Daniel J. Cosgrove
- Huck Institutes of the Life Sciences The Pennsylvania State University University Park PA USA
- Department of Biology The Pennsylvania State University University Park PA USA
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26
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Pech-Cervantes AA, Muhammad I, Ogunade IM, Jiang Y, Kim DH, Gonzalez CF, Hackmann TJ, Oliveira AS, Vyas D, Adesogan AT. Exogenous fibrolytic enzymes and recombinant bacterial expansins synergistically improve hydrolysis and in vitro digestibility of bermudagrass haylage. J Dairy Sci 2019; 102:8059-8073. [PMID: 31326164 DOI: 10.3168/jds.2019-16339] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 05/07/2019] [Indexed: 11/19/2022]
Abstract
Four experiments were conducted to examine the effects of a recombinant bacterial expansin-like protein (BsEXLX1) from Bacillus subtilis and a commercial exogenous fibrolytic enzyme (EFE) preparation for ruminants on hydrolysis of pure substrates (cellulose and xylan) and in vitro digestibility of bermudagrass haylage (BMH). Recombinant Escherichia coli BL21 strain was used to express BsEXLX1; the protein was purified using an affinity column. In experiment 1, carboxymethylcellulose, Whatman #1 filter paper (General Electric, Boston, MA) and oat-spelt xylan substrates were subjected to 4 treatments (1) sodium citrate buffer (control), (2) BsEXLX1 (162 µg/g of substrate), (3) EFE (2.3 mg/g of substrate), and (4) EFE + BsELX1 in 3 independent runs. Samples were incubated at optimal conditions for both additives (pH 5 and 50°C) or at ruminal (pH 6 and 39°C) or ambient (pH 6 and 25°C) conditions for 24 h and sugar release was measured. In experiment 2, digestibility in vitro of BMH was examined after treatment with the following: (1) control (buffer only), (2) BsEXLX1 (162 µg/g of dry matter), (3) EFE (2.2 mg/g of dry matter), and (4) EFE + BsEXLX1 in 3 independent runs at 39°C for 24 h. Experiment 3 examined effects of EFE and BsEXLX1 on simulated preingestive hydrolysis and profile of released sugars from BMH after samples were suspended in deionized water with sodium azide at 25°C for 24 h in 2 independent runs. In experiment 4, the sequence of the BsEXLX1 purified protein was compared with 447 ruminal bacterial genomes to identify similar proteins from the rumen. In experiment 1, compared with EFE alone, EFE and BsEXLX1 synergistically increased sugar release from carboxymethylcellulose and Whatman #1 filter paper under all simulated conditions; however, hydrolysis of xylan was not improved. In experiment 2, compared with EFE alone, treatment with EFE and BsEXLX1 increased neutral detergent fiber and acid detergent fiber digestibility of bermudagrass haylage (by 5.5 and 15%, respectively) and total volatile fatty acid concentrations, and decreased acetate-propionate ratio. In experiment 3, compared with EFE alone. The EFE and BsEXLX1 synergistically reduced concentrations of neutral detergent fiber and acid detergent fiber and increased release of sugars by 9.3%, particularly cellobiose (72.5%). In experiment 4, a similar sequence to that of BsEXLX1 was identified in Bacillus licheniformis, and similar hypothetical protein sequences were identified in Ruminococcus flavefaciens strains along with different protein structures in E. xylanophilum and Lachnospiraceae. This study showed that an expansin-like protein synergistically increased the hydrolysis of pure cellulose substrates and the hydrolysis and digestibility in vitro of BMH.
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Affiliation(s)
| | - I Muhammad
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32603
| | - I M Ogunade
- Department of Animal Sciences, University of Florida, Gainesville 32611; Division of Food and Animal Science, Kentucky State University, Frankfort 40601
| | - Y Jiang
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - D H Kim
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - C F Gonzalez
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32603
| | - T J Hackmann
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - A S Oliveira
- Institute of Agriculture and Environmental Sciences, Federal University of Mato Grosso, Campus Sinop, Sinop, MT, Brazil, 78890
| | - D Vyas
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - A T Adesogan
- Department of Animal Sciences, University of Florida, Gainesville 32611.
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Adesogan AT, Arriola KG, Jiang Y, Oyebade A, Paula EM, Pech-Cervantes AA, Romero JJ, Ferraretto LF, Vyas D. Symposium review: Technologies for improving fiber utilization. J Dairy Sci 2019; 102:5726-5755. [PMID: 30928262 DOI: 10.3168/jds.2018-15334] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
Abstract
The forage lignocellulosic complex is one of the greatest limitations to utilization of the nutrients and energy in fiber. Consequently, several technologies have been developed to increase forage fiber utilization by dairy cows. Physical or mechanical processing techniques reduce forage particle size and gut fill and thereby increase intake. Such techniques increase the surface area for microbial colonization and may increase fiber utilization. Genetic technologies such as brown midrib mutants (BMR) with less lignin have been among the most repeatable and practical strategies to increase fiber utilization. Newer BMR corn hybrids are better yielding than the early hybrids and recent brachytic dwarf BMR sorghum hybrids avoid lodging problems of early hybrids. Several alkalis have been effective at increasing fiber digestibility. Among these, ammoniation has the added benefit of increasing the nitrogen concentration of the forage. However, few of these have been widely adopted due to the cost and the caustic nature of the chemicals. Urea treatment is more benign but requires sufficient urease and moisture for efficacy. Ammonia-fiber expansion technology uses high temperature, moisture, and pressure to degrade lignocellulose to a greater extent than ammoniation alone, but it occurs in reactors and is therefore not currently usable on farms. Biological technologies for increasing fiber utilization such as application of exogenous fibrolytic enzymes, live yeasts, and yeast culture have had equivocal effects on forage fiber digestion in individual studies, but recent meta-analyses indicate that their overall effects are positive. Nonhydrolytic expansin-like proteins act in synergy with fibrolytic enzymes to increase fiber digestion beyond that achieved by the enzyme alone due to their ability to expand cellulose microfibrils allowing greater enzyme penetration of the cell wall matrix. White-rot fungi are perhaps the biological agents with the greatest potential for lignocellulose deconstruction, but they require aerobic conditions and several strains degrade easily digestible carbohydrates. Less ruminant nutrition research has been conducted on brown rot fungi that deconstruct lignocellulose by generating highly destructive hydroxyl radicals via the Fenton reaction. More research is needed to increase the repeatability, efficacy, cost effectiveness, and on-farm applicability of technologies for increasing fiber utilization.
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Affiliation(s)
- A T Adesogan
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611.
| | - K G Arriola
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
| | - Y Jiang
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
| | - A Oyebade
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
| | - E M Paula
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
| | - A A Pech-Cervantes
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
| | - J J Romero
- Animal and Veterinary Sciences Program, School of Food and Agriculture, University of Maine, Orono 04469
| | - L F Ferraretto
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
| | - D Vyas
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611
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Zhang F, Bunterngsook B, Li JX, Zhao XQ, Champreda V, Liu CG, Bai FW. Regulation and production of lignocellulolytic enzymes from Trichoderma reesei for biofuels production. ADVANCES IN BIOENERGY 2019. [DOI: 10.1016/bs.aibe.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Kumar V, Binod P, Sindhu R, Gnansounou E, Ahluwalia V. Bioconversion of pentose sugars to value added chemicals and fuels: Recent trends, challenges and possibilities. BIORESOURCE TECHNOLOGY 2018; 269:443-451. [PMID: 30217725 DOI: 10.1016/j.biortech.2018.08.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/09/2018] [Accepted: 08/12/2018] [Indexed: 05/12/2023]
Abstract
Most of the crop plants contain about 30% of hemicelluloses comprising D-xylose and D-arabinose. One of the major limitation for the use of pentose sugars is that high purity grade D-xylose and D-arabinose are yet to be produced as commodity chemicals. Research and developmental activities are going on in this direction for their use as platform intermediates through economically viable strategies. During chemical pretreatment of biomass, the pentose sugars were generated in the liquid stream along with other compounds. This contains glucose, proteins, phenolic compounds, minerals and acids other than pentose sugars. Arabinose is present in small amounts, which can be used for the economic production of value added compound, xylitol. The present review discusses the recent trends and developments as well as challenges and opportunities in the utilization of pentose sugars generated from lignocellulosic biomass for the production of value added compounds.
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Affiliation(s)
- Vinod Kumar
- Center of Innovative and Applied Bioprocessing, Sector 81, Mohali 160071, Punjab, India
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695019, Kerala, India
| | - Raveendran Sindhu
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695019, Kerala, India
| | - Edgard Gnansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Vivek Ahluwalia
- Center of Innovative and Applied Bioprocessing, Sector 81, Mohali 160071, Punjab, India.
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Jeong DW, Hyeon JE, Joo YC, Shin SK, Han SO. Integration of Bacterial Expansin on Agarolytic Complexes to Enhance the Degrading Activity of Red Algae by Control of Gelling Properties. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2018; 20:1-9. [PMID: 29151139 DOI: 10.1007/s10126-017-9782-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 11/07/2017] [Indexed: 06/07/2023]
Abstract
Expansin act by loosening hydrogen bonds in densely packed polysaccharides. This work characterizes the biological functions of expansin in the gelling and degradation of algal polysaccharides. In this study, the bacterial expansin BpEX from Bacillus pumilus was fused with the dockerin module of a cellulosome system for assembly with agarolytic complexes. The assembly of chimeric expansin caused an indicative enhancement in agarase activity. The enzymatic activities on agar substrate and natural biomass were 3.7-fold and 3.3-fold higher respectively than that of agarase as a single enzyme. To validate the effect on the agar degradation, the regulation potential of parameters related to gel rheology by bacterial expansin was experimentally investigated to indicate that the bacterial expansin lowered the gelling temperature and viscosity of agar. Thus, these results demonstrated the possibility of advancing more efficient strategies for utilizing agar as oligo sugar source in the biorefinery field that uses marine biomass as feedstocks.
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Affiliation(s)
- Da Woon Jeong
- Department of Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Jeong Eun Hyeon
- Department of Biotechnology, Korea University, Seoul, 02841, Republic of Korea
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19702, USA
| | - Young-Chul Joo
- Department of Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Sang Kyu Shin
- Department of Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Sung Ok Han
- Department of Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
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Duan Y, Ma Y, Zhao X, Huang R, Su R, Qi W, He Z. Real-time adsorption and action of expansin on cellulose. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:317. [PMID: 30479662 PMCID: PMC6249958 DOI: 10.1186/s13068-018-1318-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 11/13/2018] [Indexed: 05/02/2023]
Abstract
BACKGROUND Biological pretreatment is an environmentally safe method for disrupting recalcitrant structures of lignocellulose and thereby improving their hydrolysis efficiency. Expansin and expansin-like proteins act synergistically with cellulases during hydrolysis. A systematic analysis of the adsorption behavior and mechanism of action of expansin family proteins can provide a basis for the development of highly efficient pretreatment methods for cellulosic substrates using expansins. RESULTS Adsorption of Bacillus subtilis expansin (BsEXLX1) onto cellulose film under different conditions was monitored in real time using a quartz crystal microbalance with dissipation. A model was established to describe the adsorption of BsEXLX1 onto the film. High temperatures increased the initial adsorption rate while reducing the maximum amount of BsEXLX1 adsorbed onto the cellulose. Non-ionic surfactants (polyethylene glycol 4000 and Tween 80) at low concentrations enhanced BsEXLX1 adsorption; whereas, high concentrations had the opposite effect. However, sodium dodecyl sulfate inhibited adsorption at both low and high concentrations. We also investigated the structural changes of cellulose upon BsEXLX1 adsorption and found that BsEXLX1 adsorption decreased the crystallinity index, disrupted hydrogen bonding, and increased the surface area of cellulose, indicating greater accessibility of the substrate to the protein. CONCLUSIONS These results increase our understanding of the interaction between expansin and cellulose, and provide evidence for expansin treatment as a promising strategy to enhance enzymatic hydrolysis of lignocellulose.
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Affiliation(s)
- Yuhao Duan
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Yuanyuan Ma
- Biomass Conversion Laboratory of Tianjin University R&D Center for Petrochemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Xudong Zhao
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Renliang Huang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072 China
| | - Rongxin Su
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072 China
| | - Wei Qi
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072 China
| | - Zhimin He
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
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Affiliation(s)
- Daniel J. Cosgrove
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802
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Knapp A, Ripphahn M, Volkenborn K, Skoczinski P, Jaeger KE. Activity-independent screening of secreted proteins using split GFP. J Biotechnol 2017; 258:110-116. [PMID: 28619616 DOI: 10.1016/j.jbiotec.2017.05.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/31/2017] [Accepted: 05/31/2017] [Indexed: 01/16/2023]
Abstract
The large-scale industrial production of proteins requires efficient secretion, as provided, for instance, by the Sec system of Gram-positive bacteria. Protein engineering approaches to optimize secretion often involve the screening of large libraries, e.g. comprising a target protein fused to many different signal peptides. Respective high-throughput screening methods are usually based on photometric or fluorimetric assays enabling fast and simple determination of enzymatic activities. Here, we report on an alternative method for quantification of secreted proteins based on the split GFP assay. We analyzed the secretion by Bacillus subtilis of a homologous lipase and a heterologous cutinase by determination of GFP fluorescence and enzyme activity assays. Furthermore, we identified from a signal peptide library a variant of the biotechnologically relevant B. subtilis protein swollenin EXLX1 with up to 5-fold increased secretion. Our results demonstrate that the split GFP assay can be used to monitor secretion of enzymatic and non-enzymatic proteins in B. subtilis in a high-throughput manner.
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Affiliation(s)
- Andreas Knapp
- Institute of Molecular Enzyme Technology, Heinrich -Heine -University Düsseldorf, Forschungszentrum Jülich, D-52426 Jülich, Germany
| | - Myriam Ripphahn
- Institute of Molecular Enzyme Technology, Heinrich -Heine -University Düsseldorf, Forschungszentrum Jülich, D-52426 Jülich, Germany
| | - Kristina Volkenborn
- Institute of Molecular Enzyme Technology, Heinrich -Heine -University Düsseldorf, Forschungszentrum Jülich, D-52426 Jülich, Germany
| | - Pia Skoczinski
- Institute of Molecular Enzyme Technology, Heinrich -Heine -University Düsseldorf, Forschungszentrum Jülich, D-52426 Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich -Heine -University Düsseldorf, Forschungszentrum Jülich, D-52426 Jülich, Germany; Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany.
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Santos CA, Ferreira-Filho JA, O'Donovan A, Gupta VK, Tuohy MG, Souza AP. Production of a recombinant swollenin from Trichoderma harzianum in Escherichia coli and its potential synergistic role in biomass degradation. Microb Cell Fact 2017; 16:83. [PMID: 28511724 PMCID: PMC5432999 DOI: 10.1186/s12934-017-0697-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/05/2017] [Indexed: 01/09/2023] Open
Abstract
Background Fungal swollenins (SWOs) constitute a class of accessory proteins that are homologous to canonical plant expansins. Expansins and expansin-related proteins are well known for acting in the deagglomeration of cellulose structure by loosening macrofibrils. Consequently, SWOs can increase the accessibility and efficiency of the other enzymes involved in the saccharification of cellulosic substrates. Thus, SWOs are promising targets for improving the hydrolysis of plant biomass and for use as an additive to enhance the efficiency of an enzyme cocktail designed for the production of biofuels. Results Here, we report the initial characterization of an SWO from Trichoderma harzianum (ThSwo) that was successfully produced using Escherichia coli as a host. Initially, transcriptome and secretome data were used to compare swo gene expression and the amount of secreted ThSwo. The results from structural modeling and phylogenetic analysis of the ThSwo protein showed that ThSwo does preserve some structural features of the plant expansins and family-45 glycosyl hydrolase enzymes, but it evolutionarily diverges from both of these protein classes. Recombinant ThSwo was purified at a high yield and with high purity and showed secondary folding similar to that of a native fungal SWO. Bioactivity assays revealed that the purified recombinant ThSwo created a rough and amorphous surface on Avicel and displayed a high synergistic effect with a commercial xylanase from T. viride, enhancing its hydrolytic performance up to 147 ± 7%. Conclusions Many aspects of the structure and mechanism of action of fungal SWOs remain unknown. In the present study, we produced a recombinant, active SWO from T. harzianum using a prokaryotic host and confirmed its potential synergistic role in biomass degradation. Our work paves the way for further studies evaluating the structure and function of this protein, especially regarding its use in biotechnology. Electronic supplementary material The online version of this article (doi:10.1186/s12934-017-0697-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Clelton A Santos
- Molecular Glycobiotechnology Group, Department of Biochemistry, National University of Ireland Galway, Galway, Ireland.,Center for Molecular Biology and Genetic Engineering, University of Campinas, Campinas, SP, Brazil
| | - Jaire A Ferreira-Filho
- Center for Molecular Biology and Genetic Engineering, University of Campinas, Campinas, SP, Brazil
| | - Anthonia O'Donovan
- Molecular Glycobiotechnology Group, Department of Biochemistry, National University of Ireland Galway, Galway, Ireland.,Technology Centre for Biorefining and Bioenergy, Orbsen Building, National University of Ireland, Galway, Ireland
| | - Vijai K Gupta
- Molecular Glycobiotechnology Group, Department of Biochemistry, National University of Ireland Galway, Galway, Ireland.,Technology Centre for Biorefining and Bioenergy, Orbsen Building, National University of Ireland, Galway, Ireland.,Department of Chemistry and Biotechnology, ERA Chair of Green Chemistry, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Maria G Tuohy
- Molecular Glycobiotechnology Group, Department of Biochemistry, National University of Ireland Galway, Galway, Ireland.,Technology Centre for Biorefining and Bioenergy, Orbsen Building, National University of Ireland, Galway, Ireland
| | - Anete P Souza
- Center for Molecular Biology and Genetic Engineering, University of Campinas, Campinas, SP, Brazil. .,Department of Plant Biology, Biology Institute, University of Campinas, Campinas, SP, Brazil.
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Kim IJ, Seo N, An HJ, Kim JH, Harris PV, Kim KH. Type-dependent action modes of TtAA9E and TaAA9A acting on cellulose and differently pretreated lignocellulosic substrates. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:46. [PMID: 28250814 PMCID: PMC5322634 DOI: 10.1186/s13068-017-0721-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/02/2017] [Indexed: 05/15/2023]
Abstract
BACKGROUND Lytic polysaccharide monooxygenase (LPMO) is a group of recently identified proteins that catalyze oxidative cleavage of the glycosidic linkages of cellulose and other polysaccharides. By utilizing the oxidative mode of action, LPMOs are able to enhance the efficiency of cellulase in the hydrolysis of cellulose. Particularly, auxiliary activity family 9 (AA9) is a group of fungal LPMOs that show a type-dependent regioselectivity on cellulose in which Types 1, 2, and 3 hydroxylate at C1, C4, and C1 and C4 positions, respectively. In this study, we investigated comparative characteristics of TtAA9E from Thielavia terrestris belonging to Type 1 and TaAA9A from Thermoascus aurantiacus belonging to Type 3 on cellulose and pretreated lignocellulose. RESULTS From product analysis, TtAA9E dominantly generated oligosaccharides with an aldonic acid form, which is an evidence of C1 oxidation, while TaAA9A generated oligosaccharides with both aldonic acid and 4-ketoaldose forms, which is evidence of C1 and C4 oxidations, respectively. For hydrolysis of cellulose (Avicel) by cellulase, higher synergism was observed for TtAA9E than for TaAA9A. For hydrolysis of pretreated lignocellulose using rice straw, synergistic behaviors of TtAA9E and TaAA9A were different depending on the pretreatment of rice straw. Specifically, on acid-pretreated rice straw, TtAA9E showed a higher synergism than TaAA9A while on alkali-pretreated rice straw, TaAA9A showed a higher synergism than TtAA9E. CONCLUSIONS We show type-dependent action modes of TtAA9E and TaAA9A for cellulose oxidation together with substrate-dependent synergistic hydrolysis of cellulosic substrates. The results obtained from this study indicate the different behaviors of AA9s on cellulose and pretreated lignocellulose, suggesting a selection of AA9 proteins specific to substrates is required for industrial utilization.
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Affiliation(s)
- In Jung Kim
- Department of Biotechnology, Korea University, Graduate School, Seoul, 02841 South Korea
| | - Nari Seo
- Graduate School of Analytical Science & Technology and Asia-Pacific Glycomics Reference Site, Chungnam National University, Daejeon, 34134 South Korea
| | - Hyun Joo An
- Graduate School of Analytical Science & Technology and Asia-Pacific Glycomics Reference Site, Chungnam National University, Daejeon, 34134 South Korea
| | - Jae-Han Kim
- Department of Food and Nutrition, Chungnam National University, Daejeon, 34134 South Korea
| | | | - Kyoung Heon Kim
- Department of Biotechnology, Korea University, Graduate School, Seoul, 02841 South Korea
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38
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Kim IJ, Youn HJ, Kim KH. Synergism of an auxiliary activity 9 (AA9) from Chaetomium globosum with xylanase on the hydrolysis of xylan and lignocellulose. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.06.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Wang Q, Chen L, Lin H, Yu D, Shen Q, Wan L, Zhao Y. The binding, synergistic and structural characteristics of BsEXLX1 for loosening the main components of lignocellulose: Lignin, xylan, and cellulose. Enzyme Microb Technol 2016; 92:67-75. [DOI: 10.1016/j.enzmictec.2016.06.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 06/27/2016] [Accepted: 06/27/2016] [Indexed: 01/03/2023]
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40
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Eibinger M, Sigl K, Sattelkow J, Ganner T, Ramoni J, Seiboth B, Plank H, Nidetzky B. Functional characterization of the native swollenin from Trichoderma reesei: study of its possible role as C1 factor of enzymatic lignocellulose conversion. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:178. [PMID: 27570542 PMCID: PMC5000517 DOI: 10.1186/s13068-016-0590-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/15/2016] [Indexed: 05/28/2023]
Abstract
BACKGROUND Through binding to cellulose, expansin-like proteins are thought to loosen the structural order of crystalline surface material, thus making it more accessible for degradation by hydrolytic enzymes. Swollenin SWO1 is the major expansin-like protein from the fungus Trichoderma reesei. Here, we have performed a detailed characterization of a recombinant native form of SWO1 with respect to its possible auxiliary role in the enzymatic saccharification of lignocellulosic substrates. RESULTS The swo1 gene was overexpressed in T. reesei QM9414 Δxyr1 mutant, featuring downregulated cellulase production, and the protein was purified from culture supernatant. SWO1 was N-glycosylated and its circular dichroism spectrum suggested a folded protein. Adsorption isotherms (25 °C, pH 5.0, 1.0 mg substrate/mL) revealed SWO1 to be 120- and 20-fold more specific for binding to birchwood xylan and kraft lignin, respectively, than for binding to Avicel PH-101. The SWO1 binding capacity on lignin (25 µmol/g) exceeded 12-fold that on Avicel PH-101 (2.1 µmol/g). On xylan, not only the binding capacity (22 µmol/g) but also the affinity of SWO1 (K d = 0.08 µM) was enhanced compared to Avicel PH-101 (K d = 0.89 µM). SWO1 caused rapid release of a tiny amount of reducing sugars (<1 % of total) from different substrates (Avicel PH-101, nanocrystalline cellulose, steam-pretreated wheat straw, barley β-glucan, cellotetraose) but did not promote continued saccharification. Atomic force microscopy revealed that amorphous cellulose films were not affected by SWO1. Also with AFM, binding of SWO1 to cellulose nanocrystallites was demonstrated at the single-molecule level, but adsorption did not affect this cellulose. SWO1 exhibited no synergy with T. reesei cellulases in the hydrolysis of the different celluloses. However, SWO1 boosted slightly (1.5-fold) the reducing sugar release from a native grass substrate. CONCLUSIONS SWO1 is a strongly glycosylated protein, which has implications for producing it in heterologous hosts. Although SWO1 binds to crystalline cellulose, its adsorption to xylan is much stronger. SWO1 is not an auxiliary factor of the enzymatic degradation of a variety of cellulosic substrates. Effect of SWO1 on sugar release from intact plant cell walls might be exploitable with certain (e.g., mildly pretreated) lignocellulosic feedstocks.
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Affiliation(s)
- Manuel Eibinger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010 Graz, Austria
| | - Karin Sigl
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010 Graz, Austria
| | - Jürgen Sattelkow
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Thomas Ganner
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Jonas Ramoni
- Research Division Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1A/166, 1060 Vienna, Austria
| | - Bernhard Seiboth
- Research Division Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1A/166, 1060 Vienna, Austria
| | - Harald Plank
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
- Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010 Graz, Austria
- Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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Artzi L, Morag E, Shamshoum M, Bayer EA. Cellulosomal expansin: functionality and incorporation into the complex. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:61. [PMID: 26973715 PMCID: PMC4788839 DOI: 10.1186/s13068-016-0474-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/02/2016] [Indexed: 05/24/2023]
Abstract
BACKGROUND Expansins are relatively small proteins that lack enzymatic activity and are found in plants and microorganisms. The function of these proteins is to disrupt the plant cell walls by interfering with the non-covalent interchain bonding of the polysaccharides. Expansins were found to be important for plant growth, but they are also expressed by various bacteria known to have interactions with plants. Clostridium clariflavum is a plant cell wall-degrading bacterium with a highly elaborate cellulosomal system. Among its numerous dockerin-containing genes, two expansin-like proteins, Clocl_1862 and Clocl_1298 (termed herein CclEXL1 and CclEXL2) were identified, and CclEXL1 was found to be expressed as part of the cellulosome system. This is the first time that an expansin-like protein is identified in a cellulosome complex, which implicates its possible role in biomass deconstruction. RESULTS In the present article, we analyzed the functionality of CclEXL1. Its dockerin was characterized and shown to bind selectively to type-I cohesins of C. clariflavum, with preferential binding to the cohesin of ScaG, and additionally to a type-I cohesin of C. cellulolyticum. We demonstrated experimentally that the expansin-like protein binds preferentially to microcrystalline cellulose, but it also binds to acid-swollen cellulose, xylan, and wheat straw. CclEXL1 exhibited a pronounced loosening effect on filter paper, which resulted in substantial decrease in tensile stress. The C. clariflavum expansin-like protein thus enhances significantly enzymatic hydrolysis of cellulose, both by C. clariflavum cellulosomes and two major cellulosomal cellulases from this bacterium: GH48 (exoglucanase) and GH9 (endoglucanase). Finally, we demonstrated CclEXL1-mediated enhancement of microcrystalline cellulose degradation by different cellulosome fractions and the two enzymes. CONCLUSIONS The results of this study confirm that the C. clariflavum expansin-like protein is part of the elaborate cellulosome system of this bacterium with capabilities of cellulose creeping. The data suggest that pretreatment of cellulosic materials with CclEXL1 can bring about substantial improvement of hydrolysis by cellulases.
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Affiliation(s)
- Lior Artzi
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Ely Morag
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Melina Shamshoum
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Edward A. Bayer
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
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Silveira RL, Skaf MS. Molecular dynamics of the Bacillus subtilis expansin EXLX1: interaction with substrates and structural basis of the lack of activity of mutants. Phys Chem Chem Phys 2016; 18:3510-21. [DOI: 10.1039/c5cp06674c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Expansins are disruptive proteins that loosen growing plant cell walls and can enhance the enzymatic hydrolysis of cellulose.
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Affiliation(s)
| | - Munir S. Skaf
- Institute of Chemistry
- University of Campinas
- Campinas
- Brazil
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43
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Chen C, Cui Z, Song X, Liu YJ, Cui Q, Feng Y. Integration of bacterial expansin-like proteins into cellulosome promotes the cellulose degradation. Appl Microbiol Biotechnol 2015; 100:2203-12. [DOI: 10.1007/s00253-015-7071-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 10/02/2015] [Accepted: 10/07/2015] [Indexed: 01/24/2023]
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Wallenstein MD, Burns RG. Ecology of Extracellular Enzyme Activities and Organic Matter Degradation in Soil: A Complex Community-Driven Process. SSSA BOOK SERIES 2015. [DOI: 10.2136/sssabookser9.c2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
| | - Richard G. Burns
- School of Agriculture and Food Sciences; University of Queensland; Brisbane Australia
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45
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Junior AT, Dolce LG, de Oliveira Neto M, Polikarpov I. Xanthomonas campestris expansin-like X domain is a structurally disordered beta-sheet macromolecule capable of synergistically enhancing enzymatic efficiency of cellulose hydrolysis. Biotechnol Lett 2015; 37:2419-26. [DOI: 10.1007/s10529-015-1927-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 08/04/2015] [Indexed: 01/30/2023]
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46
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Research advances in expansins and expansion-like proteins involved in lignocellulose degradation. Biotechnol Lett 2015; 37:1541-51. [DOI: 10.1007/s10529-015-1842-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 04/29/2015] [Indexed: 12/12/2022]
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47
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Kim IJ, Nam KH, Yun EJ, Kim S, Youn HJ, Lee HJ, Choi IG, Kim KH. Optimization of synergism of a recombinant auxiliary activity 9 from Chaetomium globosum with cellulase in cellulose hydrolysis. Appl Microbiol Biotechnol 2015; 99:8537-47. [PMID: 25936375 PMCID: PMC4768223 DOI: 10.1007/s00253-015-6592-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 03/14/2015] [Accepted: 04/01/2015] [Indexed: 01/16/2023]
Abstract
Auxiliary activity family 9 (AA9, formerly known as glycoside hydrolase family 61 or polysaccharide monooxygenase) is a group of fungal proteins that were recently found to have a significant synergism with cellulase in cellulose hydrolysis via the oxidative cleavage of glycosidic bonds of cellulose chains. In this study, we report the active expression of a recombinant fungal AA9 from Chaetomium globosum (CgAA9) in a bacterial host, Escherichia coli, and the optimization of its synergistic activity in cellulose hydrolysis by using cellulase. The recombinant CgAA9 (0.9 mg/g cellulose) exhibited 1.7-fold synergism in the hydrolysis of Avicel when incubated with 0.9 filter paper units of Celluclast 1.5 L/g cellulose. The first study of the active expression of AA9 using a bacterial host and its synergistic optimization could be useful for the industrial application of AA9 for the saccharification of lignocellulose.
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Affiliation(s)
- In Jung Kim
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
| | - Ki Hyun Nam
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, 790-784, Republic of Korea
| | - Eun Ju Yun
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
| | - Sooah Kim
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
| | - Hak Jin Youn
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
| | - Hee Jin Lee
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
| | - In-Geol Choi
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
| | - Kyoung Heon Kim
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea.
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Haque MA, Cho KM, Barman DN, Kim MK, Yun HD. A potential cellulose microfibril swelling enzyme isolated from Bacillus sp. AY8 enhances cellulose hydrolysis. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.02.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Georgelis N, Nikolaidis N, Cosgrove DJ. Bacterial expansins and related proteins from the world of microbes. Appl Microbiol Biotechnol 2015; 99:3807-23. [PMID: 25833181 PMCID: PMC4427351 DOI: 10.1007/s00253-015-6534-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/05/2015] [Accepted: 03/09/2015] [Indexed: 12/31/2022]
Abstract
The discovery of microbial expansins emerged from studies of the mechanism of plant cell growth and the molecular basis of plant cell wall extensibility. Expansins are wall-loosening proteins that are universal in the plant kingdom and are also found in a small set of phylogenetically diverse bacteria, fungi, and other organisms, most of which colonize plant surfaces. They loosen plant cell walls without detectable lytic activity. Bacterial expansins have attracted considerable attention recently for their potential use in cellulosic biomass conversion for biofuel production, as a means to disaggregate cellulosic structures by nonlytic means ("amorphogenesis"). Evolutionary analysis indicates that microbial expansins originated by multiple horizontal gene transfers from plants. Crystallographic analysis of BsEXLX1, the expansin from Bacillus subtilis, shows that microbial expansins consist of two tightly packed domains: the N-terminal domain D1 has a double-ψ β-barrel fold similar to glycosyl hydrolase family-45 enzymes but lacks catalytic residues usually required for hydrolysis; the C-terminal domain D2 has a unique β-sandwich fold with three co-linear aromatic residues that bind β-1,4-glucans by hydrophobic interactions. Genetic deletion of expansin in Bacillus and Clavibacter cripples their ability to colonize plant tissues. We assess reports that expansin addition enhances cellulose breakdown by cellulase and compare expansins with distantly related proteins named swollenin, cerato-platanin, and loosenin. We end in a speculative vein about the biological roles of microbial expansins and their potential applications. Advances in this field will be aided by a deeper understanding of how these proteins modify cellulosic structures.
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Affiliation(s)
| | - Nikolas Nikolaidis
- Department of Biological Science, California State University, Fullerton, CA 92831, USA
| | - Daniel J. Cosgrove
- Department of Biology, Penn State University, University Park, PA 16802, USA
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Saccharification of sunflower stalks using lignocellulases from a fungal consortium comprising Pholiota adiposa and Armillaria gemina. Bioprocess Biosyst Eng 2015; 38:1645-53. [DOI: 10.1007/s00449-015-1406-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 04/19/2015] [Indexed: 10/23/2022]
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