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Hamal EK, Alfassi G, Antonenko M, Rein DM, Cohen Y. Cellulose-coated emulsion micro-particles self-assemble with yeasts for cellulose bio-conversion. Sci Rep 2024; 14:5499. [PMID: 38448579 PMCID: PMC10918086 DOI: 10.1038/s41598-024-56204-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 03/04/2024] [Indexed: 03/08/2024] Open
Abstract
In the quest for alternative renewable energy sources, a new self-assembled hybrid configuration of cellulose-coated oil-in-water emulsion particles with yeast was formed. In this research, the addition of yeasts (S. cerevisiae) to the micro-particle emulsion revealed a novel self-assembly configuration in which the yeast cell is connected to surrounding cellulose-coated micro-particles. This hybrid configuration may enhance the simultaneous saccharification and fermentation process by substrate channeling. Glucose produced by hydrolysis of the cellulose shells coating the micro-particles, catalyzed by cellulytic enzymes attached to their coating, is directly fermented to ethanol by the yeasts to which the particles are connected. The results indicate ethanol yield of 62%, based on the cellulose content of the emulsion, achieved by the yeast/micro-particle hybrids. The functionality of this hybrid configuration is expected to serve as a micro-reactor for a cascade of biochemical reactions in a "one-pot" consolidated process transforming cellulose to valuable chemicals, such as biodiesel.
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Affiliation(s)
- Ester Korkus Hamal
- Department of Chemical Engineering, Technion - Israel Institute of Technology, 3200003, Haifa, Israel.
| | - Gilad Alfassi
- Department of Biotechnology Engineering, Braude College of Engineering, Karmiel, Israel
| | - Margarita Antonenko
- Department of Chemical Engineering, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
| | - Dmitry M Rein
- Department of Chemical Engineering, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
| | - Yachin Cohen
- Department of Chemical Engineering, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
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2
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Datta R. Enzymatic degradation of cellulose in soil: A review. Heliyon 2024; 10:e24022. [PMID: 38234915 PMCID: PMC10792583 DOI: 10.1016/j.heliyon.2024.e24022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/13/2023] [Accepted: 01/02/2024] [Indexed: 01/19/2024] Open
Abstract
Cellulose degradation is a critical process in soil ecosystems, playing a vital role in nutrient cycling and organic matter decomposition. Enzymatic degradation of cellulosic biomass is the most sustainable and green method of producing liquid biofuel. It has gained intensive research interest with future perspective as the majority of terrestrial lignocellulose biomass has a great potential to be used as a source of bioenergy. However, the recalcitrant nature of lignocellulose limits its use as a source of energy. Noteworthy enough, enzymatic conversion of cellulose biomass could be a leading future technology. Fungal enzymes play a central role in cellulose degradation. Our understanding of fungal cellulases has substantially redirected in the past few years with the discovery of a new class of enzymes and Cellulosome. Efforts have been made from time to time to develop an economically viable method of cellulose degradation. This review provides insights into the current state of knowledge regarding cellulose degradation in soil and identifies areas where further research is needed.
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Affiliation(s)
- Rahul Datta
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology. Mendel University In Brno, Czech Republic
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3
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Huang Z, Ni G, Dai L, Zhang W, Feng S, Wang F. Biochemical Characterization of Novel GH6 Endoglucanase from Myxococcus sp. B6-1 and Its Effects on Agricultural Straws Saccharification. Foods 2023; 12:2517. [PMID: 37444255 DOI: 10.3390/foods12132517] [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: 05/25/2023] [Revised: 06/21/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
Cellulase has been widely used in many industrial fields, such as feed and food industry, because it can hydrolyze cellulose to oligosaccharides with a lower degree of polymerization. Endo-β-1,4-glucanase is a critical speed-limiting cellulase in the saccharification process. In this study, endo-β-1,4-glucanase gene (CelA257) from Myxococcus sp. B6-1 was cloned and expressed in Escherichia coli. CelA257 contained carbohydrate-binding module (CBM) 4-9 and glycosyl hydrolase (GH) family 6 domain that shares 54.7% identity with endoglucanase from Streptomyces halstedii. The recombinant enzyme exhibited optimal activity at pH 6.5 and 50 °C and was stable over a broad pH (6-9.5) range and temperature < 50 °C. CelA257 exhibited broad substrate specificity to barley β-glucan, lichenin, CMC, chitosan, laminarin, avicel, and phosphoric acid swollen cellulose (PASC). CelA257 degraded both cellotetrose (G4) and cellppentaose (G5) to cellobiose (G2) and cellotriose (G3). Adding CelA257 increased the release of reducing sugars in crop straw powers, including wheat straw (0.18 mg/mL), rape straw (0.42 mg/mL), rice straw (0.16 mg/mL), peanut straw (0.16 mg/mL), and corn straw (0.61 mg/mL). This study provides a potential additive in biomass saccharification applications.
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Affiliation(s)
- Zhen Huang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Guorong Ni
- College of Land Resources and Environment, Jiangxi Agriculture University, Nanchang 330045, China
| | - Longhua Dai
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Weiqi Zhang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Siting Feng
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Fei Wang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
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Fernández-López MG, Batista-García RA, Aréchiga-Carvajal ET. Alkaliphilic/Alkali-Tolerant Fungi: Molecular, Biochemical, and Biotechnological Aspects. J Fungi (Basel) 2023; 9:652. [PMID: 37367588 DOI: 10.3390/jof9060652] [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: 02/13/2023] [Revised: 05/08/2023] [Accepted: 05/08/2023] [Indexed: 06/28/2023] Open
Abstract
Biotechnologist interest in extremophile microorganisms has increased in recent years. Alkaliphilic and alkali-tolerant fungi that resist alkaline pH are among these. Alkaline environments, both terrestrial and aquatic, can be created by nature or by human activities. Aspergillus nidulans and Saccharomyces cerevisiae are the two eukaryotic organisms whose pH-dependent gene regulation has received the most study. In both biological models, the PacC transcription factor activates the Pal/Rim pathway through two successive proteolytic mechanisms. PacC is a repressor of acid-expressed genes and an activator of alkaline-expressed genes when it is in an active state. It appears, however, that these are not the only mechanisms associated with pH adaptations in alkali-tolerant fungi. These fungi produce enzymes that are resistant to harsh conditions, i.e., alkaline pH, and can be used in technological processes, such as in the textile, paper, detergent, food, pharmaceutical, and leather tanning industries, as well as in bioremediation of pollutants. Consequently, it is essential to understand how these fungi maintain intracellular homeostasis and the signaling pathways that activate the physiological mechanisms of alkali resistance in fungi.
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Affiliation(s)
- Maikel Gilberto Fernández-López
- Unidad de Manipulación Genética, Laboratorio de Micología y Fitopatología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza 66451, Mexico
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico
| | - Elva Teresa Aréchiga-Carvajal
- Unidad de Manipulación Genética, Laboratorio de Micología y Fitopatología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza 66451, Mexico
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5
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Matsumoto R, Mehjabin JJ, Noguchi H, Miyamoto T, Takasuka TE, Hori C. Genomic and Secretomic Analyses of the Newly Isolated Fungus Perenniporia fraxinea SS3 Identified CAZymes Potentially Related to a Serious Pathogenesis of Hardwood Trees. Appl Environ Microbiol 2023; 89:e0027223. [PMID: 37098943 PMCID: PMC10231188 DOI: 10.1128/aem.00272-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/06/2023] [Indexed: 04/27/2023] Open
Abstract
Perenniporia fraxinea can colonize living trees and cause severe damage to standing hardwoods by secreting a number of carbohydrate-activate enzymes (CAZymes), unlike other well-studied Polyporales. However, significant knowledge gaps exist in understanding the detailed mechanisms for this hardwood-pathogenic fungus. To address this issue, five monokaryotic P. fraxinea strains, SS1 to SS5, were isolated from the tree species Robinia pseudoacacia, and high polysaccharide-degrading activities and the fastest growth were found for P. fraxinea SS3 among the isolates. The whole genome of P. fraxinea SS3 was sequenced, and its unique CAZyme potential for tree pathogenicity was determined in comparison to the genomes of other nonpathogenic Polyporales. These CAZyme features are well conserved in a distantly related tree pathogen, Heterobasidion annosum. Furthermore, the carbon source-dependent CAZyme secretions of P. fraxinea SS3 and a nonpathogenic and strong white-rot Polyporales member, Phanerochaete chrysosporium RP78, were compared by activity measurements and proteomic analyses. As seen in the genome comparisons, P. fraxinea SS3 exhibited higher pectin-degrading activities and higher laccase activities than P. chrysosporium RP78, which were attributed to the secretion of abundant glycoside hydrolase family 28 (GH28) pectinases and auxiliary activity family 1_1 (AA1_1) laccases, respectively. These enzymes are possibly related to fungal invasion into the tree lumens and the detoxification of tree defense substances. Additionally, P. fraxinea SS3 showed secondary cell wall degradation capabilities at the same level as that of P. chrysosporium RP78. Overall, this study suggested mechanisms for how this fungus can attack the cell walls of living trees as a serious pathogen and differs from other nonpathogenic white-rot fungi. IMPORTANCE Many studies have been done to understand the mechanisms underlying the degradation of plant cell walls of dead trees by wood decay fungi. However, little is known about how some of these fungi weaken living trees as pathogens. P. fraxinea belongs to the Polyporales, a group of strong wood decayers, and is known to aggressively attack and fell standing hardwood trees all over the world. Here, we report CAZymes potentially related to plant cell wall degradation and pathogenesis factors in a newly isolated fungus, P. fraxinea SS3, by genome sequencing in conjunction with comparative genomic and secretomic analyses. The present study provides insights into the mechanisms of the degradation of standing hardwood trees by the tree pathogen, which will contribute to the prevention of this serious tree disease.
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Affiliation(s)
- Ruy Matsumoto
- Research Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Jakia Jerin Mehjabin
- Research Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
| | - Hideki Noguchi
- Center for Genome Informatics, Joint Support Center for Data Science Research, Research Organization of Information and Systems, Mishima, Shizuoka, Japan
- Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka, Japan
| | | | - Taichi E. Takasuka
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
- Global Station for Food, Land, and Water Resources, Hokkaido University, Sapporo, Japan
| | - Chiaki Hori
- Research Faculty of Engineering, Hokkaido University, Sapporo, Japan
- Research Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
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6
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Sun X, Liang Y, Wang Y, Zhang H, Zhao T, Yao B, Luo H, Huang H, Su X. Simultaneous manipulation of multiple genes within a same regulatory stage for iterative evolution of Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:26. [PMID: 35248141 PMCID: PMC8898424 DOI: 10.1186/s13068-022-02122-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 02/19/2022] [Indexed: 11/12/2022]
Abstract
Background While there is growing interest in developing non-canonical filamentous fungi as hosts for producing secretory proteins, genetic engineering of filamentous fungi for improved expression often relies heavily on the understanding of regulatory mechanisms. Results In this study, using the cellulase-producing filamentous fungus Trichoderma reesei as a model system, we designed a semi-rational strategy by arbitrarily dividing the regulation of cellulase production into three main stages-transcription, secretion, and cell metabolism. Selected regulatory or functional genes that had been experimentally verified or predicted to enhance cellulase production were overexpressed using strong inducible or constitutive promoters, while those that would inhibit cellulase production were repressed via RNAi-mediated gene silencing. A T. reesei strain expressing the surface-displayed DsRed fluorescent protein was used as the recipient strain. After three consecutive rounds of engineering, the cellulase activity increased to up to 4.35-fold and the protein concentration increased to up to 2.97-fold in the genetically modified strain. Conclusions We demonstrated that, as a proof-of-concept, selected regulatory or functional genes within an arbitrarily defined stage could be pooled to stimulate secretory cellulase production, and moreover, this method could be iteratively used for further improvement. This method is semi-rational and can essentially be used in filamentous fungi with little regulatory information. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02122-0.
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7
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Schröder GC, O'Dell WB, Webb SP, Agarwal PK, Meilleur F. Capture of activated dioxygen intermediates at the copper-active site of a lytic polysaccharide monooxygenase. Chem Sci 2022; 13:13303-13320. [PMID: 36507176 PMCID: PMC9683017 DOI: 10.1039/d2sc05031e] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/19/2022] [Indexed: 11/24/2022] Open
Abstract
Metalloproteins perform a diverse array of redox-related reactions facilitated by the increased chemical functionality afforded by their metallocofactors. Lytic polysaccharide monooxygenases (LPMOs) are a class of copper-dependent enzymes that are responsible for the breakdown of recalcitrant polysaccharides via oxidative cleavage at the glycosidic bond. The activated copper-oxygen intermediates and their mechanism of formation remains to be established. Neutron protein crystallography which permits direct visualization of protonation states was used to investigate the initial steps of oxygen activation directly following active site copper reduction in Neurospora crassa LPMO9D. Herein, we cryo-trap an activated dioxygen intermediate in a mixture of superoxo and hydroperoxo states, and we identify the conserved second coordination shell residue His157 as the proton donor. Density functional theory calculations indicate that both superoxo and hydroperoxo active site states are stable. The hydroperoxo formed is potentially an early LPMO catalytic reaction intermediate or the first step in the mechanism of hydrogen peroxide formation in the absence of substrate. We observe that the N-terminal amino group of the copper coordinating His1 remains doubly protonated directly following molecular oxygen reduction by copper. Aided by molecular dynamics and mining minima free energy calculations we establish that the conserved second-shell His161 in MtPMO3* displays conformational flexibility in solution and that this flexibility is also observed, though to a lesser extent, in His157 of NcLPMO9D. The imidazolate form of His157 observed in our structure following oxygen intermediate protonation can be attributed to abolished His157 flexibility due steric hindrance in the crystal as well as the solvent-occluded active site environment due to crystal packing. A neutron crystal structure of NcLPMO9D at low pH further supports occlusion of the active site since His157 remains singly protonated even at acidic conditions.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State UniversityRaleighNC 27695USA,Neutron Scattering Division, Oak Ridge National LaboratoryOak RidgeTN 37831USA
| | - William B. O'Dell
- Department of Molecular and Structural Biochemistry, North Carolina State UniversityRaleighNC 27695USA,Neutron Scattering Division, Oak Ridge National LaboratoryOak RidgeTN 37831USA
| | - Simon P. Webb
- VeraChem LLC12850 Middlebrook Rd. Ste 205GermantownMD 20874-5244USA
| | - Pratul K. Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State UniversityStillwaterOK 74078USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State UniversityRaleighNC 27695USA,Neutron Scattering Division, Oak Ridge National LaboratoryOak RidgeTN 37831USA
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8
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Prabmark K, Boonyapakron K, Bunterngsook B, Arunrattanamook N, Uengwetwanit T, Chitnumsub P, Champreda V. Enhancement of catalytic activity and alkaline stability of cellobiohydrolase by structure-based protein engineering. 3 Biotech 2022; 12:269. [PMID: 36097631 PMCID: PMC9463429 DOI: 10.1007/s13205-022-03339-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 08/16/2022] [Indexed: 11/30/2022] Open
Abstract
Alkaline cellobiohydrolases have the potential for application in various industries, including pulp processing and laundry where operation under high pH conditions is preferred. In this study, variants of CtCel6A cellobiohydrolase from Chaetomium thermophilum were generated by structural-based protein engineering with the rationale of increasing catalytic activity and alkaline stability. The variants included removal of the carbohydrate-binding module (CBM) and substitution of residues 173 and 200. The CBM-deleted enzyme with Y200F mutation predicted to mediate conformational change at the N-terminal loop demonstrated increased alkaline stability at 60 °C, pH 8.0 for 24 h up to 2.25-fold compared with the wild-type enzyme. Another CBM-deleted enzyme with L173E mutation predicted to induce a new hydrogen bond in the substrate-binding cleft showed enhanced hydrolysis yield of pretreated sugarcane trash up to 4.65-fold greater than that of the wild-type enzyme at the pH 8.0. The variant enzymes could thus be developed for applications on cellulose hydrolysis and plant fiber modification operated under alkaline conditions. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03339-4.
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Affiliation(s)
- Kanoknart Prabmark
- Enzyme Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
| | - Katewadee Boonyapakron
- Enzyme Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
| | - Benjarat Bunterngsook
- Enzyme Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
| | - Nattapol Arunrattanamook
- Enzyme Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
| | - Tanaporn Uengwetwanit
- Microarray Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
| | - Penchit Chitnumsub
- Biomolecular Analysis and Application Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
| | - Verawat Champreda
- Enzyme Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120 Thailand
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9
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Fan C, Zhang W, Su X, Ji W, Luo H, Zhang Y, Liu B, Yao B, Huang H, Xu X. CRISPR/Cas9-mediated genome editing directed by a 5S rRNA-tRNA Gly hybrid promoter in the thermophilic filamentous fungus Humicola insolens. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:206. [PMID: 34688310 PMCID: PMC8542335 DOI: 10.1186/s13068-021-02057-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Humicola insolens is a filamentous fungus with high potential of producing neutral and heat- and alkali-resistant cellulase. However, the genetic engineering tools, particularly the genome-editing tool, are scarce, hindering the study of cellulase expression regulation in this organism. RESULTS Herein, a CRISPR/Cas9 genome-editing system was established in H. insolens based on a hybrid 5S rRNA-tRNAGly promoter. This system is superior to the HDV (hepatitis delta virus) system in genome editing, allowing highly efficient single gene destruction in H. insolens with rates of deletion up to 84.1% (37/44). With this system, a putative pigment synthesis gene pks and the transcription factor xyr1 gene were disrupted with high efficiency. Moreover, the extracellular protein concentration and cellulase activity largely decreased when xyr1 was deleted, demonstrating for the first time that Xyr1 plays an important role in cellulase expression regulation. CONCLUSIONS The established CRISPR/Cas9 system is a powerful genetic operation tool for H. insolens, which will accelerate studies on the regulation mechanism of cellulase expression and engineering of H. insolens for higher cellulase production.
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Affiliation(s)
- Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Xiaoyun Su
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Wangli Ji
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Huiying Luo
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bin Yao
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Huoqing Huang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China.
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China.
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10
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Jönsson C, Wei R, Biundo A, Landberg J, Schwarz Bour L, Pezzotti F, Toca A, M. Jacques L, Bornscheuer UT, Syrén P. Biocatalysis in the Recycling Landscape for Synthetic Polymers and Plastics towards Circular Textiles. CHEMSUSCHEM 2021; 14:4028-4040. [PMID: 33497036 PMCID: PMC8518944 DOI: 10.1002/cssc.202002666] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/26/2021] [Indexed: 05/05/2023]
Abstract
Although recovery of fibers from used textiles with retained material quality is desired, separation of individual components from polymer blends used in today's complex textile materials is currently not available at viable scale. Biotechnology could provide a solution to this pressing problem by enabling selective depolymerization of recyclable fibers of natural and synthetic origin, to isolate constituents or even recover monomers. We compiled experimental data for biocatalytic polymer degradation with a focus on synthetic polymers with hydrolysable links and calculated conversion rates to explore this path The analysis emphasizes that we urgently need major research efforts: beyond cellulose-based fibers, biotechnological-assisted depolymerization of plastics so far only works for polyethylene terephthalate, with degradation of a few other relevant synthetic polymer chains being reported. In contrast, by analyzing market data and emerging trends for synthetic fibers in the textile industry, in combination with numbers from used garment collection and sorting plants, it was shown that the use of difficult-to-recycle blended materials is rapidly growing. If the lack of recycling technology and production trend for fiber blends remains, a volume of more than 3400 Mt of waste will have been accumulated by 2030. This work highlights the urgent need to transform the textile industry from a biocatalytic perspective.
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Affiliation(s)
- Christina Jönsson
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Ren Wei
- Department of Biotechnology and Enzyme CatalysisInstitute of BiochemistryUniversity of GreifswaldFelix-Hausdorff-Strasse 417487GreifswaldGermany
| | - Antonino Biundo
- School of Engineering Sciences in ChemistryBiotechnology and HealthKTH Royal Institute of TechnologyScience for Life LaboratoryTomtebodavägen 23, Box 1031 171 21 SolnaStockholmSweden
- School of Engineering Sciences in ChemistryBiotechnology and HealthDepartment of Fibre and Polymer TechnologyKTH Royal Institute of TechnologyTeknikringen 56–58100 44StockholmSweden
- Present address: REWOW srlVia Cardinale Agostino Ciasca 9701 24BariItaly
| | - Johan Landberg
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Lisa Schwarz Bour
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Fabio Pezzotti
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Andreea Toca
- Swedish StockingsTyskbagargatan 7114 43StockholmSweden
- Present address: Hyper IslandVirkesvägen 2120 30StockholmSweden
| | - Les M. Jacques
- The LYCRA Company UK Limited60, Clooney Road, MaydownLondonderry N.BT47 6THIreland
| | - Uwe T. Bornscheuer
- Department of Biotechnology and Enzyme CatalysisInstitute of BiochemistryUniversity of GreifswaldFelix-Hausdorff-Strasse 417487GreifswaldGermany
| | - Per‐Olof Syrén
- School of Engineering Sciences in ChemistryBiotechnology and HealthKTH Royal Institute of TechnologyScience for Life LaboratoryTomtebodavägen 23, Box 1031 171 21 SolnaStockholmSweden
- School of Engineering Sciences in ChemistryBiotechnology and HealthDepartment of Fibre and Polymer TechnologyKTH Royal Institute of TechnologyTeknikringen 56–58100 44StockholmSweden
- KTH Royal Institute of TechnologySchool of Engineering Sciences in Chemistry, Biotechnology and Health Wallenberg Wood Science CenterTeknikringen 56–58100 44StockholmSweden
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11
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Schröder GC, Meilleur F. Metalloprotein catalysis: structural and mechanistic insights into oxidoreductases from neutron protein crystallography. Acta Crystallogr D Struct Biol 2021; 77:1251-1269. [PMID: 34605429 PMCID: PMC8489226 DOI: 10.1107/s2059798321009025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
Metalloproteins catalyze a range of reactions, with enhanced chemical functionality due to their metal cofactor. The reaction mechanisms of metalloproteins have been experimentally characterized by spectroscopy, macromolecular crystallography and cryo-electron microscopy. An important caveat in structural studies of metalloproteins remains the artefacts that can be introduced by radiation damage. Photoreduction, radiolysis and ionization deriving from the electromagnetic beam used to probe the structure complicate structural and mechanistic interpretation. Neutron protein diffraction remains the only structural probe that leaves protein samples devoid of radiation damage, even when data are collected at room temperature. Additionally, neutron protein crystallography provides information on the positions of light atoms such as hydrogen and deuterium, allowing the characterization of protonation states and hydrogen-bonding networks. Neutron protein crystallography has further been used in conjunction with experimental and computational techniques to gain insight into the structures and reaction mechanisms of several transition-state metal oxidoreductases with iron, copper and manganese cofactors. Here, the contribution of neutron protein crystallography towards elucidating the reaction mechanism of metalloproteins is reviewed.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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12
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Abstract
Enzymes are widely used in the food industry. Their use as a supplement to the raw material for animal feed is a current research topic. Although there are several studies on the application of enzyme additives in the animal feed industry, it is necessary to search for new enzymes, as well as to utilize bioinformatics tools for the design of specific enzymes that work in certain environmental conditions and substrates. This will allow the improvement of the productive parameters in animals, reducing costs and making the processes more efficient. Technological needs have considered these catalysts as essential in many industrial sectors and research is constantly being carried out to optimize their use in those processes. This review describes the enzymes used in animal nutrition, their mode of action, their production and new sources of production as well as studies on different animal models to evaluate their effect on the productive performance intended for the production of animal feed.
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13
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Natural Products of the Fungal Genus Humicola: Diversity, Biological Activity, and Industrial Importance. Curr Microbiol 2021; 78:2488-2509. [PMID: 34003333 DOI: 10.1007/s00284-021-02533-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 05/03/2021] [Indexed: 12/21/2022]
Abstract
Fungal metabolites are worthily taken into account as a pool of synthetically interesting and remarkably important new lead compounds for medical, agricultural, and chemical industries. Humicola species are known to have biotechnological and industrial potentials. Humicola genus (family Chaetomiaceae) is a prosperous fountainhead of unique and structurally diverse metabolites that have various bioactivities. Moreover, Humicola species attract substantial attention for their marked ability to produce thermostable enzymes with biotechnological and industrial importance. This review highlights the published researches on the isolated metabolites from the genus Humicola and their biological activities as well as the industrial importance of Humicola species. In the current review, more than 50 compounds are described and 84 references are cited.
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14
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From lignocellulose to plastics: Knowledge transfer on the degradation approaches by fungi. Biotechnol Adv 2021; 50:107770. [PMID: 33989704 DOI: 10.1016/j.biotechadv.2021.107770] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/04/2021] [Accepted: 05/08/2021] [Indexed: 01/21/2023]
Abstract
In this review, we argue that there is much to be learned by transferring knowledge from research on lignocellulose degradation to that on plastic. Plastic waste accumulates in the environment to hazardous levels, because it is inherently recalcitrant to biological degradation. Plants evolved lignocellulose to be resistant to degradation, but with time, fungi became capable of utilising it for their nutrition. Examples of how fungal strategies to degrade lignocellulose could be insightful for plastic degradation include how fungi overcome the hydrophobicity of lignin (e.g. production of hydrophobins) and crystallinity of cellulose (e.g. oxidative approaches). In parallel, knowledge of the methods for understanding lignocellulose degradation could be insightful such as advanced microscopy, genomic and post-genomic approaches (e.g. gene expression analysis). The known limitations of biological lignocellulose degradation, such as the necessity for physiochemical pretreatments for biofuel production, can be predictive of potential restrictions of biological plastic degradation. Taking lessons from lignocellulose degradation for plastic degradation is also important for biosafety as engineered plastic-degrading fungi could also have increased plant biomass degrading capabilities. Even though plastics are significantly different from lignocellulose because they lack hydrolysable C-C or C-O bonds and therefore have higher recalcitrance, there are apparent similarities, e.g. both types of compounds are mixtures of hydrophobic polymers with amorphous and crystalline regions, and both require hydrolases and oxidoreductases for their degradation. Thus, many lessons could be learned from fungal lignocellulose degradation.
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15
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Schröder GC, O’Dell WB, Swartz PD, Meilleur F. Preliminary results of neutron and X-ray diffraction data collection on a lytic polysaccharide monooxygenase under reduced and acidic conditions. Acta Crystallogr F Struct Biol Commun 2021; 77:128-133. [PMID: 33830078 PMCID: PMC8034432 DOI: 10.1107/s2053230x21002399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/02/2021] [Indexed: 11/10/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-center enzymes that are involved in the oxidative cleavage of the glycosidic bond in crystalline cellulose and other polysaccharides. The LPMO reaction is initiated by the addition of a reductant and oxygen to ultimately form an unknown activated copper-oxygen species that is responsible for polysaccharide-substrate H-atom abstraction. Given the sensitivity of metalloproteins to radiation damage, neutron protein crystallography provides a nondestructive technique for structural characterization while also informing on the positions of H atoms. Neutron cryo-crystallography permits the trapping of catalytic intermediates, thereby providing insight into the protonation states and chemical nature of otherwise short-lived species in the reaction mechanism. To characterize the reaction-mechanism intermediates of LPMO9D from Neurospora crassa, a cryo-neutron diffraction data set was collected from an ascorbate-reduced crystal. A second neutron diffraction data set was collected at room temperature from an LPMO9D crystal exposed to low-pH conditions to probe the protonation states of ionizable groups involved in catalysis under acidic conditions.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - William B. O’Dell
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Paul D. Swartz
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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16
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de Boer C, McGregor NGS, Peterse E, Schröder SP, Florea BI, Jiang J, Reijngoud J, Ram AFJ, van Wezel GP, van der Marel GA, Codée JDC, Overkleeft HS, Davies GJ. Glycosylated cyclophellitol-derived activity-based probes and inhibitors for cellulases. RSC Chem Biol 2020; 1:148-155. [PMID: 34458755 PMCID: PMC8341922 DOI: 10.1039/d0cb00045k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/15/2020] [Indexed: 11/24/2022] Open
Abstract
Cellulases and related β-1,4-glucanases are essential components of lignocellulose-degrading enzyme mixtures. The detection of β-1,4-glucanase activity typically relies on monitoring the breakdown of purified lignocellulose-derived substrates or synthetic chromogenic substrates, limiting the activities which can be detected and complicating the tracing of activity back to specific components within complex enzyme mixtures. As a tool for the rapid detection and identification of β-1,4-glucanases, a series of glycosylated cyclophellitol inhibitors mimicking β-1,4-glucan oligosaccharides have been synthesised. These compounds are highly efficient inhibitors of HiCel7B, a well-known GH7 endo-β-1,4-glucanase. An elaborated activity-based probe facilitated the direct detection and identification of β-1,4-glucanases within a complex fungal secretome without any detectable cross-reactivity with β-d-glucosidases. These probes and inhibitors add valuable new capacity to the growing toolbox of cyclophellitol-derived probes for the activity-based profiling of biomass-degrading enzymes.
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Affiliation(s)
- Casper de Boer
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Nicholas G S McGregor
- York Structural Biology Laboratory, Department of Chemistry, The University of York Heslington York YO10 5DD UK
| | - Evert Peterse
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Sybrin P Schröder
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Bogdan I Florea
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Jianbing Jiang
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Jos Reijngoud
- Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Arthur F J Ram
- Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Gilles P van Wezel
- Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | | | - Jeroen D C Codée
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Herman S Overkleeft
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2300 RA Leiden The Netherlands
| | - Gideon J Davies
- York Structural Biology Laboratory, Department of Chemistry, The University of York Heslington York YO10 5DD UK
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17
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Chen F, Ye J, Sista Kameshwar AK, Wu X, Ren J, Qin W, Li DW. A Novel Cold-Adaptive Endo-1,4-β-Glucanase From Burkholderia pyrrocinia JK-SH007: Gene Expression and Characterization of the Enzyme and Mode of Action. Front Microbiol 2020; 10:3137. [PMID: 32038571 PMCID: PMC6987409 DOI: 10.3389/fmicb.2019.03137] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/26/2019] [Indexed: 11/30/2022] Open
Abstract
The efficient industrial conversion of plant-derived cellulose to simple sugars and other value-added chemicals requires various highly stable and reactive enzymes. Industrial processes especially synchronous saccharification and fermentation (SSF)-based production of cellulosic bio-ethanol require enzymes that are active at lower temperatures. In this study, we have identified, characterized, and expressed the cold-adaptive endo-1,4-β-glucanase (BpEG) isolated from the Burkholderia pyrrocinia JK-SH007. The analysis of the predicted amino acid sequence indicated that BpEG belongs to GH family 8. The BpEG without the signal peptide was cloned into the expression vector pET32a and significantly expressed in Escherichia coli BL21 (DE3) competent cells. The SDS-PAGE and Western blot analysis of BpEG revealed that the recombinant BpEG was approximately 60 kDa. Purified recombinant BpEG exhibited hydrolytic activity against carboxymethyl cellulose (CMC) and phosphoric acid swollen cellulose (PASC), but not crystalline cellulose and xylan substrates. High performance, anion exchange, chromatography-pulsed amperometric detector (HPAEC-PAD) analysis of the enzymatic products obtained from depolymerization of 1,4-β-linked biopolymers of different lengths revealed an interesting cutting mechanism employed by endoglucanases. The recombinant BpEG exhibited 6.0 of optimum pH and 35°C of optimum temperature, when cultured with CMC substrate. The BpEG enzyme exhibited stable activity between pH 5.0 and 9.0 at 35°C. Interestingly, BpEG retained about 42% of its enzymatic activity at 10°C compared to its optimal temperature. This new cold-adaptive cellulase could potentially achieve synchronous saccharification and fermentation (SSF) making BpEG a promising candidate in the fields of biofuel, biorefining, food and pharmaceutical industries.
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Affiliation(s)
- Feifei Chen
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China.,Department of Biology, Lakehead University, Thunder Bay, ON, Canada
| | - Jianren Ye
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | | | - Xuelian Wu
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Jiahong Ren
- Department of Biology Science and Technology, Changzhi College, Changzhi, China
| | - Wensheng Qin
- Department of Biology, Lakehead University, Thunder Bay, ON, Canada
| | - De-Wei Li
- Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China.,The Connecticut Agricultural Experiment Station, Valley Laboratory, Windsor, CT, United States
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18
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Røjel N, Kari J, Sørensen TH, Borch K, Westh P. pH profiles of cellulases depend on the substrate and architecture of the binding region. Biotechnol Bioeng 2019; 117:382-391. [PMID: 31631319 DOI: 10.1002/bit.27206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/09/2019] [Accepted: 10/13/2019] [Indexed: 01/06/2023]
Abstract
Understanding the pH effect of cellulolytic enzymes is of great technological importance. In this study, we have examined the influence of pH on activity and stability for central cellulases (Cel7A, Cel7B, Cel6A from Trichoderma reesei, and Cel7A from Rasamsonia emersonii). We systematically changed pH from 2 to 7, temperature from 20°C to 70°C, and used both soluble (4-nitrophenyl β- d-lactopyranoside [pNPL]) and insoluble (Avicel) substrates at different concentrations. Collective interpretation of these data provided new insights. An unusual tolerance to acidic conditions was observed for both investigated Cel7As, but only on real insoluble cellulose. In contrast, pH profiles on pNPL were bell-shaped with a strong loss of activity both above and below the optimal pH for all four enzymes. On a practical level, these observations call for the caution of the common practice of using soluble substrates for the general characterization of pH effects on cellulase activity. Kinetic modeling of the experimental data suggested that the nucleophile of Cel7A experiences a strong downward shift in pKa upon complexation with an insoluble substrate. This shift was less pronounced for Cel7B, Cel6A, and for Cel7A acting on the soluble substrate, and we hypothesize that these differences are related to the accessibility of water to the binding region of the Michaelis complex.
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Affiliation(s)
- Nanna Røjel
- Department of Science and Environment (INM), Roskilde University, Roskilde, Denmark.,Present address: Department of Biotechnology and Biomedicine, Technical University of Denmark, Building 224, DK-2800, Kgs. Lyngby, Denmark
| | - Jeppe Kari
- Department of Science and Environment (INM), Roskilde University, Roskilde, Denmark.,Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | | | | | - Peter Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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19
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Ballmann P, Lightfoot J, Müller M, Dröge S, Prade R. Redesigning the Aspergillus nidulans xylanase regulatory pathway to enhance cellulase production with xylose as the carbon and inducer source. Microb Cell Fact 2019; 18:193. [PMID: 31699093 PMCID: PMC6839167 DOI: 10.1186/s12934-019-1243-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/24/2019] [Indexed: 11/10/2022] Open
Abstract
Background Biomass contains cellulose (C6-sugars), hemicellulose (C5-sugars) and lignin. Biomass ranks amongst the most abundant hydrocarbon resources on earth. However, biomass is recalcitrant to enzymatic digestion by cellulases. Physicochemical pretreatment methods make cellulose accessible but partially destroy hemicellulose, producing a C5-sugar-rich liquor. Typically, digestion of pretreated LCB is performed with commercial cellulase preparations, but C5-sugars could in principle be used for “on site” production of cellulases by genetically engineered microorganism, thereby reducing costs. Results Here we report a succession of genetic interventions in Aspergillus nidulans that redesign the natural regulatory circuitry of cellulase genes in such a way that recombinant strains use C5-sugar liquors (xylose) to grow a vegetative tissue and simultaneously accumulate large amounts of cellulases. Overexpression of XlnR showed that under xylose-induction conditions only xylanase C was produced. XlnR overexpression strains were constructed that use the xynCp promoter to drive the production of cellobiohydrolases, endoglucanases and β-glucosidase. All five cellulases accumulated at high levels when grown on xylose. Production of cellulases in the presence of pretreated-biomass C5-sugar liquors was investigated, and cellulases accumulated to much higher enzyme titers than those obtained for traditional fungal cell factories with cellulase-inducing substrates. Conclusions By replacing expensive substrates with a cheap by-product carbon source, the use of C5-sugar liquors directly derived from LCB pretreatment processes not only reduces enzyme production costs, but also lowers operational costs by eliminating the need for off-site enzyme production, purification, concentration, transport and dilution.
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Affiliation(s)
- Patrick Ballmann
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Jorge Lightfoot
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Michael Müller
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Stephan Dröge
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Rolf Prade
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA.
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20
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Xu X, Fan C, Song L, Li J, Chen Y, Zhang Y, Liu B, Zhang W. A Novel CreA-Mediated Regulation Mechanism of Cellulase Expression in the Thermophilic Fungus Humicola insolens. Int J Mol Sci 2019; 20:ijms20153693. [PMID: 31357701 PMCID: PMC6696435 DOI: 10.3390/ijms20153693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/23/2019] [Accepted: 07/26/2019] [Indexed: 12/24/2022] Open
Abstract
The thermophilic fungus Humicola insolens produces cellulolytic enzymes that are of great scientific and commercial interest; however, few reports have focused on its cellulase expression regulation mechanism. In this study, we constructed a creA gene (carbon catabolite repressor gene) disruption mutant strain of H. insolens that exhibited a reduced radial growth rate and stouter hyphae compared to the wild-type (WT) strain. The creA disruption mutant also expressed elevated pNPCase (cellobiohydrolase activities), pNPGase (β-glucosidase activities), and xylanase levels in non-inducing fermentation with glucose. Unlike other fungi, the H. insolenscreA disruption mutant displayed lower FPase (filter paper activity), CMCase (carboxymethyl cellulose activity), pNPCase, and pNPGase activity than observed in the WT strain when fermentation was induced using Avicel, whereas its xylanase activity was higher than that of the parental strain. These results indicate that CreA acts as a crucial regulator of hyphal growth and is part of a unique cellulase expression regulation mechanism in H. insolens. These findings provide a new perspective to improve the understanding of carbon catabolite repression regulation mechanisms in cellulase expression, and enrich the knowledge of metabolism diversity and molecular regulation of carbon metabolism in thermophilic fungi.
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Affiliation(s)
- Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Liya Song
- Beijing Key Lab of Plant Resource Research and Development, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
| | - Jinyang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Yuan Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China.
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China.
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21
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Yadav SK, Singh R, Singh PK, Vasudev PG. Insecticidal fern protein Tma12 is possibly a lytic polysaccharide monooxygenase. PLANTA 2019; 249:1987-1996. [PMID: 30903269 DOI: 10.1007/s00425-019-03135-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 03/09/2019] [Indexed: 05/25/2023]
Abstract
Amino acid sequence and crystal structure analyses of Tma12, an insecticidal protein isolated from the fern Tectaria macrodonta, identify it as a carbohydrate-binding protein belonging to the AA10 family of lytic polysaccharide monooxygenases, and provide the first evidence of AA10 proteins in plants. Tma12, isolated from the fern Tectaria macrodonta, is a next-generation insecticidal protein. Transgenic cotton expressing Tma12 exhibits resistance against whitefly and viral diseases. Beside its insecticidal property, the structure and function of Tma12 are unknown. This limits understanding of the insecticidal mechanism of the protein and targeted improvement in its efficacy. Here we report the amino acid sequence analysis and the crystal structure of Tma12, suggesting that it is possibly a lytic polysaccharide monooxygenase (LPMO) of the AA10 family. Amino acid sequence of Tma12 shows 45% identity with a cellulolytic LPMO of Streptomyces coelicolor. The crystal structure of Tma12, obtained at 2.2 Å resolution, possesses all the major structural characteristics of AA10 LPMOs. A H2O2-based enzymatic assay also supports this finding. It is the first report of the occurrence of LPMO-like protein in a plant. The two facts that Tma12 possesses insecticidal activity and shows structural similarity with LPMOs collectively advocate exploration of microbial LPMOs for insecticidal potential.
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Affiliation(s)
- Sunil K Yadav
- Genetics and Plant Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India
| | - Rahul Singh
- Genetics and Plant Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India
| | - Pradhyumna Kumar Singh
- Genetics and Plant Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India.
| | - Prema G Vasudev
- Metabolic and Structural Biology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India.
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22
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Busch A, Danchin EGJ, Pauchet Y. Functional diversification of horizontally acquired glycoside hydrolase family 45 (GH45) proteins in Phytophaga beetles. BMC Evol Biol 2019; 19:100. [PMID: 31077129 PMCID: PMC6509783 DOI: 10.1186/s12862-019-1429-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/26/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cellulose, a major polysaccharide of the plant cell wall, consists of β-1,4-linked glucose moieties forming a molecular network recalcitrant to enzymatic breakdown. Although cellulose is potentially a rich source of energy, the ability to degrade it is rare in animals and was believed to be present only in cellulolytic microbes. Recently, it has become clear that some animals encode endogenous cellulases belonging to several glycoside hydrolase families (GHs), including GH45. GH45s are distributed patchily among the Metazoa and, in insects, are encoded only by the genomes of Phytophaga beetles. This study aims to understand both the enzymatic functions and the evolutionary history of GH45s in these beetles. RESULTS To this end, we biochemically assessed the enzymatic activities of 37 GH45s derived from five species of Phytophaga beetles and discovered that beetle-derived GH45s degrade three different substrates: amorphous cellulose, xyloglucan and glucomannan. Our phylogenetic and gene structure analyses indicate that at least one gene encoding a putative cellulolytic GH45 was present in the last common ancestor of the Phytophaga, and that GH45 xyloglucanases evolved several times independently in these beetles. The most closely related clade to Phytophaga GH45s was composed of fungal sequences, suggesting this GH family was acquired by horizontal gene transfer from fungi. Besides the insects, other arthropod GH45s do not share a common origin and appear to have emerged at least three times independently. CONCLUSION The rise of functional innovation from gene duplication events has been a fundamental process in the evolution of GH45s in Phytophaga beetles. Both, enzymatic activity and ancestral origin suggest that GH45s were likely an essential prerequisite for the adaptation allowing Phytophaga beetles to feed on plants.
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Affiliation(s)
- André Busch
- Entomology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | | | - Yannick Pauchet
- Entomology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany.
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Wei H, Wang W, Alper HS, Xu Q, Knoshaug EP, Van Wychen S, Lin CY, Luo Y, Decker SR, Himmel ME, Zhang M. Ameliorating the Metabolic Burden of the Co-expression of Secreted Fungal Cellulases in a High Lipid-Accumulating Yarrowia lipolytica Strain by Medium C/N Ratio and a Chemical Chaperone. Front Microbiol 2019; 9:3276. [PMID: 30687267 PMCID: PMC6333634 DOI: 10.3389/fmicb.2018.03276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/17/2018] [Indexed: 12/19/2022] Open
Abstract
Yarrowia lipolytica, known to accumulate lipids intracellularly, lacks the cellulolytic enzymes needed to break down solid biomass directly. This study aimed to evaluate the potential metabolic burden of expressing core cellulolytic enzymes in an engineered high lipid-accumulating strain of Y. lipolytica. Three fungal cellulases, Talaromyces emersonii-Trichoderma reesei chimeric cellobiohydrolase I (chimeric-CBH I), T. reesei cellobiohydrolase II (CBH II), and T. reesei endoglucanase II (EG II) were expressed using three constitutive strong promoters as a single integrative expression block in a recently engineered lipid hyper-accumulating strain of Y. lipolytica (HA1). In yeast extract-peptone-dextrose (YPD) medium, the resulting cellulase co-expressing transformant YL165-1 had the chimeric-CBH I, CBH II, and EG II secretion titers being 26, 17, and 132 mg L-1, respectively. Cellulase co-expression in YL165-1 in culture media with a moderate C/N ratio of ∼4.5 unexpectedly resulted in a nearly two-fold reduction in cellular lipid accumulation compared to the parental control strain, a sign of cellular metabolic drain. Such metabolic drain was ameliorated when grown in media with a high C/N ratio of 59 having a higher glucose utilization rate that led to approximately twofold more cell mass and threefold more lipid production per liter culture compared to parental control strain, suggesting cross-talk between cellulase and lipid production, both of which involve the endoplasmic reticulum (ER). Most importantly, we found that the chemical chaperone, trimethylamine N-oxide dihydride increased glucose utilization, cell mass and total lipid titer in the transformants, suggesting further amelioration of the metabolic drain. This is the first study examining lipid production in cellulase-expressing Y. lipolytica strains under various C/N ratio media and with a chemical chaperone highlighting the metabolic complexity for developing robust, cellulolytic and lipogenic yeast strains.
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Affiliation(s)
- Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Wei Wang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Hal S Alper
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Qi Xu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Eric P Knoshaug
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Stefanie Van Wychen
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States.,National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Chien-Yuan Lin
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Yonghua Luo
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Stephen R Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Michael E Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Min Zhang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States.,National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
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Busch A, Kunert G, Wielsch N, Pauchet Y. Cellulose degradation in Gastrophysa viridula (Coleoptera: Chrysomelidae): functional characterization of two CAZymes belonging to glycoside hydrolase family 45 reveals a novel enzymatic activity. INSECT MOLECULAR BIOLOGY 2018; 27:633-650. [PMID: 29774620 DOI: 10.1111/imb.12500] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cellulose is a major component of the primary and secondary cell walls in plants. Cellulose is considered to be the most abundant biopolymer on Earth and represents a large potential source of metabolic energy. Yet, cellulose degradation is rare and mostly restricted to cellulolytic microorganisms. Recently, various metazoans, including leaf beetles, have been found to encode their own cellulases, giving them the ability to degrade cellulose independently of cellulolytic symbionts. Here, we analyzed the cellulosic capacity of the leaf beetle Gastrophysa viridula, which typically feeds on Rumex plants. We identified three putative cellulases member of two glycoside hydrolase (GH) families, namely GH45 and GH9. Using heterologous expression and functional assays, we demonstrated that both GH45 proteins are active enzymes, in contrast to the GH9 protein. One GH45 protein acted on amorphous cellulose as an endo-β-1,4-glucanase, whereas the other evolved to become an endo-β-1,4-xyloglucanase. We successfully knocked down the expression of both GH45 genes using RNAi, but no changes in weight gain or mortality were observed compared to control insects. Our data indicated that the breakdown of these polysaccharides in G. viridula may facilitate access to plant cell content, which is rich in nitrogen and simple sugars.
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Affiliation(s)
- A Busch
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - G Kunert
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - N Wielsch
- Research Group Mass Spectrometry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Y Pauchet
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
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25
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Using response surface methodology in combination with Plackett-Burman design for optimization of culture media and extracellular expression of Trichoderma reesei synthetic endoglucanase II in Escherichia coli. Mol Biol Rep 2018; 45:1197-1208. [PMID: 30032381 DOI: 10.1007/s11033-018-4272-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
Cellulases like endoglucanase II (EGII) from Trichoderma reesei are the industrial enzymes responsible for breakdown of cellulosic materials. Due to its importance for production of eco-friendly commercial products such as alternative biofuels, industrial EGII production and optimization of its production conditions merit consideration. The gene responsible for EGII expression was designed and sub-cloned in to pET26b expression vector and transformed into BL21 (DE3) pLysS cells. Protein expression and purification was followed by a RSM design (20 experiments) to optimize the IPTG Concentration, post induction period and cell density (OD600). Thereafter, another RSM design (20 experiments) was performed to find and optimize the most important permeabilizing factors to achieve higher extracellular EGII expression. The EGII expression levels were assessed by Ghose method. The EGII gene was sub-cloned and protein expression and purification were successfully performed. The RSM experiments indicated that 0.331 mM for IPTG Concentration, 10.89 H for post induction period and 3.41 for cell density (OD600) were the optimum culture. Glycine (0.99%), Triton X-100 (0.73%) and CaCl2 (0.232) have been assigned as the most effective membrane permeabalizing factors. Optimization of culture medium components has led to a 3.06 fold increase in extracellular expression of EGII. RSM is an amenable method to optimize the expression of commercially significant enzymes. Our results indicated that optimization of IPTG concentration, post induction period and cell density along with glycine, Triton X-100 and Ca2+ concentration could lead to more cost effective industrial production of EGII.
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The use of Agrobacterium-mediated insertional mutagenesis sequencing to identify novel genes of Humicola insolens involved in cellulase production. 3 Biotech 2018; 8:153. [PMID: 29492372 DOI: 10.1007/s13205-018-1166-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/09/2018] [Indexed: 10/17/2022] Open
Abstract
A transfer DNA (T-DNA)-tagged mutant library of Humicola insolens was screened for mutants with altered cellulase production using the plate-clearing zone assay. Three selected mutants (5-A7, 5-C6, and 13-B7) exhibited significantly depressed FPase, CMCase and xylanase activities compared with the wild-type strain upon shake-flask fermentation, while the pNPCase and pNPGase activities of the three mutants were relatively higher than those of the parental strain. Combined with the results of SDS-PAGE and mass spectrometry, we suggest that expression of the CMCases Cel6B, Cel7B, CMC3, and XynA/B/C was reduced in the mutant strains. Twelve putative T-DNA insertion sites were identified in the three mutants via Agrobacterium-mediated insertional mutagenesis sequencing (AIM-Seq). Bioinformatics analysis suggested that a putative dolichyl pyrophosphate phosphatase, two hypothetical proteins encoding genes of unknown function, and/or nine intergenic fragments may be involved in cellulase and hemicellulase production by H. insolens. This provides promising new candidate genes relevant to cellulase production by the fungus, which will be crucial not only for our understanding of the molecular mechanism underlying cellulase production, but also for strain improvement.
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27
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Li J, Xu X, Shi P, Liu B, Zhang Y, Zhang W. Overexpression and characterization of a novel endo-β-1,3(4)-glucanase from thermophilic fungus Humicola insolens Y1. Protein Expr Purif 2017; 138:63-68. [DOI: 10.1016/j.pep.2015.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/10/2015] [Accepted: 11/15/2015] [Indexed: 11/27/2022]
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Abstract
Fungi and fungal enzymes play important roles in the new bioeconomy. Enzymes from filamentous fungi can unlock the potential of recalcitrant lignocellulose structures of plant cell walls as a new resource, and fungi such as yeast can produce bioethanol from the sugars released after enzyme treatment. Such processes reflect inherent characteristics of the fungal way of life, namely, that fungi as heterotrophic organisms must break down complex carbon structures of organic materials to satisfy their need for carbon and nitrogen for growth and reproduction. This chapter describes major steps in the conversion of plant biomass to value-added products. These products provide a basis for substituting fossil-derived fuels, chemicals, and materials, as well as unlocking the biomass potential of the agricultural harvest to yield more food and feed. This article focuses on the mycological basis for the fungal contribution to biorefinery processes, which are instrumental for improved resource efficiency and central to the new bioeconomy. Which types of processes, inherent to fungal physiology and activities in nature, are exploited in the new industrial processes? Which families of the fungal kingdom and which types of fungal habitats and ecological specializations are hot spots for fungal biomass conversion? How can the best fungal enzymes be found and optimized for industrial use? How can they be produced most efficiently-in fungal expression hosts? How have industrial biotechnology and biomass conversion research contributed to mycology and environmental research? Future perspectives and approaches are listed, highlighting the importance of fungi in development of the bioeconomy.
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29
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Impact of Module-X2 and Carbohydrate Binding Module-3 on the catalytic activity of associated glycoside hydrolases towards plant biomass. Sci Rep 2017. [PMID: 28623337 PMCID: PMC5473887 DOI: 10.1038/s41598-017-03927-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Cellulolytic enzymes capable of hydrolyzing plant biomass are secreted by microbial cells specifically in response to the carbon substrate present in the environment. These enzymes consist of a catalytic domain, generally appended to one or more non-catalytic Carbohydrate Binding Module (CBM), which enhances their activity towards recalcitrant biomass. In the present study, the genome of a cellulolytic microbe Paenibacillus polymyxa A18 was annotated for the presence of CBMs and analyzed their expression in response to the plant biomass and model polysaccharides Avicel, CMC and xylan using quantitative PCR. A gene that encodes X2-CBM3 was found to be maximally induced in response to the biomass and crystalline substrate Avicel. Association of X2-CBM3 with xyloglucanase and endoglucanase led to up to 4.6-fold increase in activity towards insoluble substrates. In the substrate binding study, module X2 showed a higher affinity towards biomass and phosphoric acid swollen cellulose, whereas CBM3 showed a higher affinity towards Avicel. Further structural modeling of X2 also indicated its potential role in substrate binding. Our findings highlighted the role of module X2 along with CBM3 in assisting the enzyme catalysis of agricultural residue and paved the way to engineer glycoside hydrolases for superior activity.
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30
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Kogo T, Yoshida Y, Koganei K, Matsumoto H, Watanabe T, Ogihara J, Kasumi T. Production of rice straw hydrolysis enzymes by the fungi Trichoderma reesei and Humicola insolens using rice straw as a carbon source. BIORESOURCE TECHNOLOGY 2017; 233:67-73. [PMID: 28258998 DOI: 10.1016/j.biortech.2017.01.075] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/20/2017] [Accepted: 01/21/2017] [Indexed: 06/06/2023]
Abstract
Rice straw was evaluated as a carbon source for the fungi, Trichoderma reesei and Humicola insolens, to produce enzymes for rice straw hydrolysis. The enzyme activity of T. reesei and H. insolens cultivated in medium containing non-treated rice straw were almost equivalent to the enzyme of T. reesei cultivated in Avicel medium, a form of refined cellulose. The enzyme activity of T. reesei cultivated in medium containing NH4OH-treated rice straw was 4-fold higher than enzyme from cultures grown in Avicel medium. In contrast, H. insolens enzyme from cultures grown in NH4OH-treated rice straw had significantly lower activity compared with non-treated rice straw or Avicel. The combined use of T. reesei and H. insolens enzymes resulted in a significant synergistic enhancement in enzymatic activity. Our data suggest that rice straw is a promising low-cost carbon source for fungal enzyme production for rice straw hydrolysis.
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Affiliation(s)
- Takashi Kogo
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Yuki Yoshida
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Keisuke Koganei
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Hitoshi Matsumoto
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Taisuke Watanabe
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Jun Ogihara
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Takafumi Kasumi
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.
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31
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Ben Hmad I, Gargouri A. Neutral and alkaline cellulases: Production, engineering, and applications. J Basic Microbiol 2017; 57:653-658. [PMID: 28503798 DOI: 10.1002/jobm.201700111] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/18/2017] [Accepted: 04/21/2017] [Indexed: 01/08/2023]
Abstract
Neutral and alkaline cellulases from microorganisms constitute a major group of the industrial enzymes and find applications in various industries. Screening is the important ways to get novel cellulases. Most fungal cellulases have acidic pH optima, except some fungi like Humicola insolens species. However, new applications require the use of neutral and alkaline cellulases in food, brewery and wine, animal feed, textile and laundry, pulp and paper industries, agriculture as well in scientific research purposes. Indeed, the demand for these enzymes is growing more rapidly than ever before, and becomes the driving force for research on engineering the cellulolytic enzymes. Here, we present an overview of the biotechnological research for neutral and alkaline cellulases.
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Affiliation(s)
- Ines Ben Hmad
- Laboratory of Molecular Biology of Eukaryotes, Centre of Biotechnology of Sfax CBS/University of Sfax, Sfax, Tunisia
| | - Ali Gargouri
- Laboratory of Molecular Biology of Eukaryotes, Centre of Biotechnology of Sfax CBS/University of Sfax, Sfax, Tunisia
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32
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Ben Hmad I, Boudabbous M, Belghith H, Gargouri A. A novel ionic liquid-stable halophilic endoglucanase from Stachybotrys microspora. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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33
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Zhang G, Liu P, Wei W, Wang X, Wei D, Wang W. A light-switchable bidirectional expression system in filamentous fungus Trichoderma reesei. J Biotechnol 2016; 240:85-93. [PMID: 27816655 DOI: 10.1016/j.jbiotec.2016.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/30/2016] [Accepted: 11/01/2016] [Indexed: 11/16/2022]
Abstract
The filamentous fungi Trichoderma reesei is widely used in the production of cellulolytic enzymes and recombinant proteins. However, only moderate success has been achieved in expressing heterologous proteins in T. reesei. Light-dependent control of DNA transcription, and protein expression have been demonstrated in bacteria, fungi, and mammalian cells. In this study, light inducible transactivators, a "light-on" bidirectional promoter and a "light-off" promoter were constructed successfully in T. reesei for the first time. Our light inducible transactivators can homodimerize and bind to the upstream region of artificial promoters to activate or repress genes transcription. Additionally, we upgraded the light-inducible system to on-off system that can simultaneously control the expression of multiple heterologous proteins in T. reesei. Moreover, a native cellulase-free background for the expression of heterologous proteins was achieved by knocking out the genes involved in transcriptional regulation and encoding of cellulases: xyr1, cbh1, and cbh2. Our light-switchable system showed a very little background protein expression and robust activation in the blue light with significantly improved heterologous protein expression. We demonstrate that our light-switchable system has a potential application as an on/off "switch" that can simultaneously regulate the expression of multiple genes in T. reesei under native cellulase-free background.
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Affiliation(s)
- Guoxiu Zhang
- State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Pei Liu
- State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Wei Wei
- State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Xuedong Wang
- State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Dongzhi Wei
- State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Wei Wang
- State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China.
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34
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Xu X, Li J, Shi P, Ji W, Liu B, Zhang Y, Yao B, Fan Y, Zhang W. The use of T-DNA insertional mutagenesis to improve cellulase production by the thermophilic fungus Humicola insolens Y1. Sci Rep 2016; 6:31108. [PMID: 27506519 PMCID: PMC4979032 DOI: 10.1038/srep31108] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/11/2016] [Indexed: 11/21/2022] Open
Abstract
Humicola insolens is an excellent producer of pH-neutral active, thermostable cellulases that find many industrial applications. In the present study, we developed an efficient Agrobacterium tumefaciens-mediated transformation system for H. insolens. We transformed plasmids carrying the promoter of the glyceraldehyde-3-phosphate dehydrogenase gene of H. insolens driving the transcription of genes encoding neomycin phosphotransferase, hygromycin B phosphotransferase, and enhanced green fluorescent protein. We optimized transformation efficiency to obtain over 300 transformants/106 conidia. T-DNA insertional mutagenesis was employed to generate an H. insolens mutant library, and we isolated a transformant termed T4 with enhanced cellulase and hemicellulase activities. The FPase, endoglucanase, cellobiohydrolase, β-glucosidase, and xylanase activities of T4, measured at the end of fermentation, were 60%, 440%, 320%, 41%, and 81% higher than those of the wild-type strain, respectively. We isolated the sequences flanking the T-DNA insertions and thus identified new genes potentially involved in cellulase and hemicellulase production. Our results show that it is feasible to use T-DNA insertional mutagenesis to identify novel candidate genes involved in cellulase production. This will be valuable when genetic improvement programs seeking to enhance cellulase production are planned, and will also allow us to gain a better understanding of the genetics of the thermophilic fungus H. insolens.
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Affiliation(s)
- Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jinyang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Pengjun Shi
- Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wangli Ji
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Bin Yao
- Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yunliu Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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35
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Xia W, Bai Y, Cui Y, Xu X, Qian L, Shi P, Zhang W, Luo H, Zhan X, Yao B. Functional diversity of family 3 β-glucosidases from thermophilic cellulolytic fungus Humicola insolens Y1. Sci Rep 2016; 6:27062. [PMID: 27271847 PMCID: PMC4897640 DOI: 10.1038/srep27062] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 05/09/2016] [Indexed: 11/09/2022] Open
Abstract
The fungus Humicola insolens is one of the most powerful decomposers of crystalline cellulose. However, studies on the β-glucosidases from this fungus remain insufficient, especially on glycosyl hydrolase family 3 enzymes. In the present study, we analyzed the functional diversity of three distant family 3 β-glucosidases from Humicola insolens strain Y1, which belonged to different evolutionary clades, by heterogeneous expression in Pichia pastoris strain GS115. The recombinant enzymes shared similar enzymatic properties including thermophilic and neutral optima (50-60 °C and pH 5.5-6.0) and high glucose tolerance, but differed in substrate specificities and kinetics. HiBgl3B was solely active towards aryl β-glucosides while HiBgl3A and HiBgl3C showed broad substrate specificities including both disaccharides and aryl β-glucosides. Of the three enzymes, HiBgl3C exhibited the highest specific activity (158.8 U/mg on pNPG and 56.4 U/mg on cellobiose) and catalytic efficiency and had the capacity to promote cellulose degradation. Substitutions of three key residues Ile48, Ile278 and Thr484 of HiBgl3B to the corresponding residues of HiBgl3A conferred the enzyme activity towards sophorose, and vice versa. This study reveals the functional diversity of GH3 β-glucosidases as well as the key residues in recognizing +1 subsite of different substrates.
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Affiliation(s)
- Wei Xia
- College of Animal Science, Zhejiang University, Hangzhou 310058, People's Republic of China.,Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Yingguo Bai
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Ying Cui
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Lichun Qian
- College of Animal Science, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Pengjun Shi
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Xiuan Zhan
- College of Animal Science, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
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36
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Book AJ, Lewin GR, McDonald BR, Takasuka TE, Wendt-Pienkowski E, Doering DT, Suh S, Raffa KF, Fox BG, Currie CR. Evolution of High Cellulolytic Activity in Symbiotic Streptomyces through Selection of Expanded Gene Content and Coordinated Gene Expression. PLoS Biol 2016; 14:e1002475. [PMID: 27276034 PMCID: PMC4898821 DOI: 10.1371/journal.pbio.1002475] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 05/05/2016] [Indexed: 11/23/2022] Open
Abstract
The evolution of cellulose degradation was a defining event in the history of life. Without efficient decomposition and recycling, dead plant biomass would quickly accumulate and become inaccessible to terrestrial food webs and the global carbon cycle. On land, the primary drivers of plant biomass deconstruction are fungi and bacteria in the soil or associated with herbivorous eukaryotes. While the ecological importance of plant-decomposing microbes is well established, little is known about the distribution or evolution of cellulolytic activity in any bacterial genus. Here we show that in Streptomyces, a genus of Actinobacteria abundant in soil and symbiotic niches, the ability to rapidly degrade cellulose is largely restricted to two clades of host-associated strains and is not a conserved characteristic of the Streptomyces genus or host-associated strains. Our comparative genomics identify that while plant biomass degrading genes (CAZy) are widespread in Streptomyces, key enzyme families are enriched in highly cellulolytic strains. Transcriptomic analyses demonstrate that cellulolytic strains express a suite of multi-domain CAZy enzymes that are coregulated by the CebR transcriptional regulator. Using targeted gene deletions, we verify the importance of a highly expressed cellulase (GH6 family cellobiohydrolase) and the CebR transcriptional repressor to the cellulolytic phenotype. Evolutionary analyses identify complex genomic modifications that drive plant biomass deconstruction in Streptomyces, including acquisition and selective retention of CAZy genes and transcriptional regulators. Our results suggest that host-associated niches have selected some symbiotic Streptomyces for increased cellulose degrading activity and that symbiotic bacteria are a rich biochemical and enzymatic resource for biotechnology. Cellulose deconstruction helps shape the global carbon cycle; this study shows that high cellulolytic ability evolved in select lineages of the bacterial genus Streptomyces through key changes in gene content and transcriptional regulation. Only specific microbes can deconstruct the vast stores of carbon within plant biomass. Studying the distribution, diversity, and evolution of these cellulolytic organisms improves our understanding of the ecological functions of microbes in the environment and their contributions to the global carbon cycle. The bacterial genus Streptomyces is abundant in soil, appears to readily form symbiotic associations with eukaryotic hosts, and has long been thought to contribute to plant biomass degradation. Here, we show that the ability to rapidly deconstruct cellulose is surprisingly rare in the genus Streptomyces but is enriched in symbiotic stains associated with diverse insect hosts that feed on plant biomass. By using a combination of genomic, transcriptomic, and genetic analyses, we identify key changes in gene content and expression that confer cellulolytic activity. Our results support the idea that a complex interplay of genomic changes, occurring over ancient time scales, shapes the evolution of the ecologically important ability to deconstruct plant biomass.
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Affiliation(s)
- Adam J. Book
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Gina R. Lewin
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Bradon R. McDonald
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Taichi E. Takasuka
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Evelyn Wendt-Pienkowski
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Drew T. Doering
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Steven Suh
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kenneth F. Raffa
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Brian G. Fox
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Cameron R. Currie
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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Sinitsyn AP, Korotkova OG, Sinitsyna OA, Rozhkova AM, Dotsenko GS, Proskurina OV, Osipov DO, Kondrat’eva EG, Chekushina AV. Optimizing the composition of cellulase enzyme complex from Penicillium verruculosum: Enhancing hydrolytic capabilities via genetic engineering. CATALYSIS IN INDUSTRY 2016. [DOI: 10.1134/s2070050416010128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Yucatán in black and red: Linking edaphic analysis and pyrosequencing-based assessment of bacterial and fungal community structures in the two main kinds of soil of Yucatán State. Microbiol Res 2016; 188-189:23-33. [PMID: 27296959 DOI: 10.1016/j.micres.2016.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/16/2016] [Accepted: 04/21/2016] [Indexed: 12/11/2022]
Abstract
Yucatán State is dominated by two kinds of soil, named "Black Leptosol" and "Red Leptosol", which are interwoven across the State. In this work, we analyzed the relation between the edaphic characteristics and the bacterial and fungal community structures in these two kinds of Leptosol. The results revealed that Black Leptosol (BlaS) had a higher content of calcium carbonates, organic matter, nitrogen, and phosphorus than Red Leptosol (RedS). The most outstanding difference in the bacterial community structure between BlaS and RedS was that while in BlaS Actinobacteria was the most abundant phylum (43.7%), followed by Acidobacteria (26.9%) and Proteobacteria (23.6%), in RedS the bacterial community was strongly dominated by Acidobacteria (83%). Two fungal phyla were identified in both kinds of soil; Ascomycota, with 77% in BlaS and 56% in RedS, and Basidiomycota, with 22% in RedS and only 0.67% in BlaS. The most relevant difference between the two fungal communities was that excepting for Fusarium sp., all the species they had were different. Thus, in contrast with bacterial communities, where most of the major OTUs were present in both kinds of soil, fungal communities appeared to be unique to each kind of Leptosol.
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Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability. PLoS One 2016; 11:e0151840. [PMID: 26999749 PMCID: PMC4801328 DOI: 10.1371/journal.pone.0151840] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/05/2016] [Indexed: 11/25/2022] Open
Abstract
Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation.
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40
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Gómez S, López-Estepa M, Fernández FJ, Suárez T, Vega MC. Alternative Eukaryotic Expression Systems for the Production of Proteins and Protein Complexes. ADVANCED TECHNOLOGIES FOR PROTEIN COMPLEX PRODUCTION AND CHARACTERIZATION 2016; 896:167-84. [DOI: 10.1007/978-3-319-27216-0_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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41
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Imran M, Anwar Z, Irshad M, Asad MJ, Ashfaq H. Cellulase Production from Species of Fungi and Bacteria from Agricultural Wastes and Its Utilization in Industry: A Review. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/aer.2016.42005] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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42
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Kim DY, Lee MJ, Cho HY, Lee JS, Lee MH, Chung CW, Shin DH, Rhee YH, Son KH, Park HY. Genetic and functional characterization of an extracellular modular GH6 endo-β-1,4-glucanase from an earthworm symbiont, Cellulosimicrobium funkei HY-13. Antonie van Leeuwenhoek 2015; 109:1-12. [PMID: 26481128 DOI: 10.1007/s10482-015-0604-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
Abstract
The gene (1608-bp) encoding a GH6 endo-β-1,4-glucanase (CelL) from the earthworm-symbiotic bacterium Cellulosimicrobium funkei HY-13 was cloned from its whole genome sequence, expressed recombinantly, and biochemically characterized. CelL (56.0 kDa) is a modular enzyme consisting of an N-terminal catalytic GH6 domain (from Val57 to Pro396), which is 71 % identical to a GH6 protein (accession no.: WP_034662937) from Cellulomonas sp. KRMCY2, together with a C-terminal CBM 2 domain (from Cys429 to Cys532). The highest catalytic activity of CelL toward carboxymethylcellulose (CMC) was observed at 50 °C and pH 5.0, and was relatively stable at a broad pH range of 4.0-10.0. The enzyme was capable of efficiently hydrolyzing the cellulosic polymers in the order of barley β-1,3-1,4-D-glucan > CMC > lichenan > Avicel > konjac glucomannan. However, cellobiose, cellotriose, p-nitrophenyl derivatives of mono- and disaccharides, or structurally unrelated carbohydrate polymers including β-1,3-D-glucan, β-1,4-D-galactomannan, and β-1,4-D-xylan were not susceptible to CelL. The enzymatic hydrolysis of cellopentaose resulted in the production of a mixture of 68.6 % cellobiose and 31.4 % cellotriose but barley β-1,3-1,4-D-glucan was 100 % degraded to cellotriose by CelL. The enzyme strongly bound to Avicel, ivory nut mannan, and chitin but showed relatively weak binding affinity to lichenan, lignin, or poly(3-hydroxybutyrate) granules.
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Affiliation(s)
- Do Young Kim
- Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea
| | - Min Ji Lee
- Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea
| | - Han-Young Cho
- Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea
| | - Jong Suk Lee
- Gyeonggi Bio-Center, Gyeonggi Institute of Science & Technology Promotion, Suwon, 443-270, Republic of Korea
| | - Mi-Hwa Lee
- Division of Metabolism and Functionality Research, Korea Food Research Institute (KFRI), Sungnam, 463-746, Republic of Korea
| | - Chung Wook Chung
- Department of Biological Sciences, Andong National University, Andong, 760-749, Republic of Korea
| | - Dong-Ha Shin
- Insect Biotech Co. Ltd., Daejeon, 305-811, Republic of Korea
| | - Young Ha Rhee
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, 305-764, Republic of Korea
| | - Kwang-Hee Son
- Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea.
| | - Ho-Yong Park
- Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 305-806, Republic of Korea.
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43
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Cellulolytic Streptomyces strains associated with herbivorous insects share a phylogenetically linked capacity to degrade lignocellulose. Appl Environ Microbiol 2015; 80:4692-701. [PMID: 24837391 DOI: 10.1128/aem.01133-14] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Actinobacteria in the genus Streptomyces are critical players in microbial communities that decompose complex carbohydrates in the soil, and these bacteria have recently been implicated in the deconstruction of plant polysaccharides for some herbivorous insects. Despite the importance of Streptomyces to carbon cycling, the extent of their plant biomass-degrading ability remains largely unknown. In this study, we compared four strains of Streptomyces isolated from insect herbivores that attack pine trees: DpondAA-B6 (SDPB6) from the mountain pine beetle, SPB74 from the southern pine beetle, and SirexAA-E (SACTE) and SirexAA-G from the woodwasp, Sirex noctilio. Biochemical analysis of secreted enzymes demonstrated that only two of these strains, SACTE and SDPB6, were efficient at degrading plant biomass. Genomic analyses indicated that SACTE and SDPB6 are closely related and that they share similar compositions of carbohydrate-active enzymes. Genome-wide proteomic and transcriptomic analyses revealed that the major exocellulases (GH6 and GH48), lytic polysaccharide monooxygenases (AA10), and mannanases (GH5) were conserved and secreted by both organisms, while the secreted endocellulases (GH5 and GH9 versus GH9 and GH12) were from diverged enzyme families. Together, these data identify two phylogenetically related insect-associated Streptomyces strains with high biomass-degrading activity and characterize key enzymatic similarities and differences used by these organisms to deconstruct plant biomass.
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44
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Xu X, Li J, Zhang W, Huang H, Shi P, Luo H, Liu B, Zhang Y, Zhang Z, Fan Y, Yao B. A Neutral Thermostable β-1,4-Glucanase from Humicola insolens Y1 with Potential for Applications in Various Industries. PLoS One 2015; 10:e0124925. [PMID: 25909505 PMCID: PMC4409357 DOI: 10.1371/journal.pone.0124925] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 03/10/2015] [Indexed: 01/26/2023] Open
Abstract
We cloned a new glycoside hydrolase family 6 gene, Hicel6C, from the thermophilic fungus Humicola insolens Y1 and expressed it in Pichia pastoris. Using barley β-glucan as a substrate, recombinant HiCel6C protein exhibited neutral pH (6.5) and high temperature (70°C) optima. Distinct from most reported acidic fungal endo-β-1,4-glucanases, HiCel6C was alkali-tolerant, retaining greater than 98.0, 61.2, and 27.6% of peak activity at pH 8.0, 9.0, and 10.0, respectively, and exhibited good stability over a wide pH range (pH 5.0−11.0) and at temperatures up to 60°C. The Km and Vmax values of HiCel6C for barley β-glucan were 1.29 mg/mL and 752 μmol/min·mg, respectively. HiCel6C was strictly specific for the β-1,4-glucoside linkage exhibiting activity toward barley β-glucan, lichenan, and carboxy methylcellulose sodium salt (CMC-Na), but not toward laminarin (1,3-β-glucan). HiCel6C cleaved the internal glycosidic linkages of cellooligosaccharides randomly and thus represents an endo-cleaving enzyme. The predominant product of polysaccharide hydrolysis by HiCel6C was cellobiose, suggesting that it functions by an endo-processive mechanism. The favorable properties of HiCel6C make it a good candidate for basic research and for applications in the textile and brewing industries.
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Affiliation(s)
- Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jinyang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- * E-mail: (WZ); (BY)
| | - Huoqing Huang
- Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Pengjun Shi
- Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huiying Luo
- Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhifang Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yunliu Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Bin Yao
- Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- * E-mail: (WZ); (BY)
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Madsen JK, Pihl R, Møller AH, Madsen AT, Otzen DE, Andersen KK. The anionic biosurfactant rhamnolipid does not denature industrial enzymes. Front Microbiol 2015; 6:292. [PMID: 25941516 PMCID: PMC4400916 DOI: 10.3389/fmicb.2015.00292] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/24/2015] [Indexed: 11/13/2022] Open
Abstract
Biosurfactants (BS) are surface-active molecules produced by microorganisms. Their combination of useful properties and sustainable production make them promising industrial alternatives to petrochemical and oleochemical surfactants. Here we compare the impact of the anionic BS rhamnolipid (RL) and the conventional/synthetic anionic surfactant sodium dodecyl sulfate (SDS) on the structure and stability of three different commercially used enzymes, namely the cellulase Carezyme® (CZ), the phospholipase Lecitase Ultra® (LT) and the α-amylase Stainzyme® (SZ). Our data reveal a fundamental difference in their mode of interaction. SDS shows great diversity of interaction toward the different enzymes. It efficiently unfolds both LT and CZ, but LT is unfolded by SDS through formation of SDS clusters on the enzyme well below the cmc, while CZ is only unfolded by bulk micelles and on average binds significantly less SDS than LT. SDS binds with even lower stoichiometry to SZ and leads to an increase in thermal stability. In contrast, RL does not affect the tertiary or secondary structure of any enzyme at room temperature, has little impact on thermal stability and only binds detectably (but at low stoichiometries) to SZ. Furthermore, all enzymes maintain activity at both monomeric and micellar concentrations of RL. We conclude that RL, despite its anionic charge, is a surfactant that does not compromise the structural integrity of industrially relevant enzymes. This makes RL a promising alternative to current synthetic anionic surfactants in a wide range of commercial applications.
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Affiliation(s)
| | | | | | | | - Daniel E. Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark
| | - Kell K. Andersen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark
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46
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Payne CM, Knott BC, Mayes HB, Hansson H, Himmel ME, Sandgren M, Ståhlberg J, Beckham GT. Fungal Cellulases. Chem Rev 2015; 115:1308-448. [DOI: 10.1021/cr500351c] [Citation(s) in RCA: 533] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christina M. Payne
- Department
of Chemical and Materials Engineering and Center for Computational
Sciences, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, Kentucky 40506, United States
| | - Brandon C. Knott
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Heather B. Mayes
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Henrik Hansson
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Michael E. Himmel
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mats Sandgren
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Jerry Ståhlberg
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Gregg T. Beckham
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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Lakhundi S, Siddiqui R, Khan NA. Cellulose degradation: a therapeutic strategy in the improved treatment of Acanthamoeba infections. Parasit Vectors 2015; 8:23. [PMID: 25586209 PMCID: PMC4300153 DOI: 10.1186/s13071-015-0642-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/05/2015] [Indexed: 11/10/2022] Open
Abstract
Acanthamoeba is an opportunistic free-living amoeba that can cause blinding keratitis and fatal brain infection. Early diagnosis, followed by aggressive treatment is a pre-requisite in the successful treatment but even then the prognosis remains poor. A major drawback during the course of treatment is the ability of the amoeba to enclose itself within a shell (a process known as encystment), making it resistant to chemotherapeutic agents. As the cyst wall is partly made of cellulose, thus cellulose degradation offers a potential therapeutic strategy in the effective targeting of trophozoite encased within the cyst walls. Here, we present a comprehensive report on the structure of cellulose and cellulases, as well as known cellulose degradation mechanisms with an eye to target the Acanthamoeba cyst wall. The disruption of the cyst wall will make amoeba (concealed within) susceptible to chemotherapeutic agents, and at the very least inhibition of the excystment process will impede infection recurrence, as we bring these promising drug targets into focus so that they can be explored to their fullest.
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Affiliation(s)
- Sahreena Lakhundi
- Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan.
| | - Ruqaiyyah Siddiqui
- Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan.
| | - Naveed Ahmed Khan
- Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan.
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48
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The characterization of the endoglucanase Cel12A from Gloeophyllum trabeum reveals an enzyme highly active on β-glucan. PLoS One 2014; 9:e108393. [PMID: 25251390 PMCID: PMC4177221 DOI: 10.1371/journal.pone.0108393] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 08/21/2014] [Indexed: 11/19/2022] Open
Abstract
The basidiomycete fungus Gloeophyllum trabeum causes a typical brown rot and is known to use reactive oxygen species in the degradation of cellulose. The extracellular Cel12A is one of the few endo-1,4-β-glucanase produced by G. trabeum. Here we cloned cel12A and heterologously expressed it in Aspergillus niger. The identity of the resulting recombinant protein was confirmed by mass spectrometry. We used the purified GtCel12A to determine its substrate specificity and basic biochemical properties. The G. trabeum Cel12A showed highest activity on β-glucan, followed by lichenan, carboxymethylcellulose, phosphoric acid swollen cellulose, microcrystalline cellulose, and filter paper. The optimal pH and temperature for enzymatic activity were, respectively, 4.5 and 50°C on β-glucan. Under these conditions specific activity was 239.2±9.1 U mg−1 and the half-life of the enzyme was 84.6±3.5 hours. Thermofluor studies revealed that the enzyme was most thermal stable at pH 3. Using β-glucan as a substrate, the Km was 3.2±0.5 mg mL−1 and the Vmax was 0.41±0.02 µmol min−1. Analysis of the effects of GtCel12A on oat spelt and filter paper by scanning electron microscopy revealed the morphological changes taking place during the process.
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Construction of a promoter collection for genes co-expression in filamentous fungus Trichoderma reesei. J Ind Microbiol Biotechnol 2014; 41:1709-18. [PMID: 25209688 DOI: 10.1007/s10295-014-1508-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022]
Abstract
Trichoderma reesei is the preferred organism for producing industrial cellulases. However, cellulases derived from T. reesei have their highest activity at acidic pH. When the pH value increased above 7, the enzyme activities almost disappeared, thereby limiting the application of fungal cellulases under neutral or alkaline conditions. A lot of heterologous alkaline cellulases have been successfully expressed in T. reesei to improve its cellulolytic profile. To our knowledge, there are few reports describing the co-expression of two or more heterologous cellulases in T. reesei. We designed and constructed a promoter collection for gene expression and co-expression in T. reesei. Taking alkaline cellulase as a reporter gene, we assessed our promoters with strengths ranging from 4 to 106 % as compared to the pWEF31 expression vector (Lv D, Wang W, Wei D (2012) Construction of two vectors for gene expression in Trichoderma reesei. Plasmid 67(1):67-71). The promoter collection was used in a proof-of-principle approach to achieve the co-expression of an alkaline endoglucanase and an alkaline cellobiohydrolase. We observed higher activities of both cellulose degradation and biostoning by the co-expression of an endoglucanase and a cellobiohydrolase than the activities obtained by the expression of only endoglucanase or cellobiohydrolase. This study makes the process of engineering expression of multiple genes easier in T. reesei.
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50
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Geethu C, Nair RA. Purification and biochemical characterization of an extracellular endoglucanase from the necrotrophic oomycete,Pythium myriotylumDreschler. J Basic Microbiol 2014; 54:1322-30. [DOI: 10.1002/jobm.201400323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/05/2014] [Indexed: 12/24/2022]
Affiliation(s)
- C. Geethu
- School of Biotechnology; National Institute of Technology Calicut (NITC); Calicut Kerala India
| | - R. Aswati Nair
- School of Biotechnology; National Institute of Technology Calicut (NITC); Calicut Kerala India
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