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Artzi L, Bayer EA, Moraïs S. Cellulosomes: bacterial nanomachines for dismantling plant polysaccharides. Nat Rev Microbiol 2017; 15:83-95. [PMID: 27941816 DOI: 10.1038/nrmicro.2016.164] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cellulosomes are multienzyme complexes that are produced by anaerobic cellulolytic bacteria for the degradation of lignocellulosic biomass. They comprise a complex of scaffoldin, which is the structural subunit, and various enzymatic subunits. The intersubunit interactions in these multienzyme complexes are mediated by cohesin and dockerin modules. Cellulosome-producing bacteria have been isolated from a large variety of environments, which reflects their prevalence and the importance of this microbial enzymatic strategy. In a given species, cellulosomes exhibit intrinsic heterogeneity, and between species there is a broad diversity in the composition and configuration of cellulosomes. With the development of modern technologies, such as genomics and proteomics, the full protein content of cellulosomes and their expression levels can now be assessed and the regulatory mechanisms identified. Owing to their highly efficient organization and hydrolytic activity, cellulosomes hold immense potential for application in the degradation of biomass and are the focus of much effort to engineer an ideal microorganism for the conversion of lignocellulose to valuable products, such as biofuels.
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Affiliation(s)
- Lior Artzi
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - Sarah Moraïs
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
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102
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Chen L, Mulchandani A, Ge X. Spore-displayed enzyme cascade with tunable stoichiometry. Biotechnol Prog 2017; 33:383-389. [PMID: 27977916 DOI: 10.1002/btpr.2416] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/02/2016] [Indexed: 12/18/2022]
Abstract
Taking the advantages of inert and stable nature of endospores, we developed a biocatalysis platform for multiple enzyme immobilization on Bacillus subtilis spore surface. Among B. subtilis outer coat proteins, CotG mediated a high expression level of Clostridium thermocellum cohesin (CtCoh) with a functional display capability of ∼104 molecules per spore of xylose reductase-C. thermocellum dockerin fusion protein (XR-CtDoc). By co-immobilization of phosphite dehydrogenase (PTDH) on spore surface via Ruminococcus flavefaciens cohesin-dockerin modules, regeneration of NADPH was achieved. Both xylose reductase (XR) and PTDH exhibited enhanced stability upon spore surface display. More importantly, by altering the copy numbers of CtCoh and RfCoh fused with CotG, the molar ratio between immobilized enzymes was adjusted in a controllable manner. Optimization of spore-displayed XR/PTDH stoichiometry resulted in increased yields of xylitol. In conclusion, endospore surface display presents a novel approach for enzyme cascade immobilization with improved stability and tunable stoichiometry. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:383-389, 2017.
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Affiliation(s)
- Long Chen
- Dept. of Chemical and Environmental Engineering, University of California, Riverside, CA, 92521
| | - Ashok Mulchandani
- Dept. of Chemical and Environmental Engineering, University of California, Riverside, CA, 92521
| | - Xin Ge
- Dept. of Chemical and Environmental Engineering, University of California, Riverside, CA, 92521
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103
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Ji P, Zhang Y, Wang J, Zhao F. MetaSort untangles metagenome assembly by reducing microbial community complexity. Nat Commun 2017; 8:14306. [PMID: 28112173 PMCID: PMC5264255 DOI: 10.1038/ncomms14306] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/14/2016] [Indexed: 12/31/2022] Open
Abstract
Most current approaches to analyse metagenomic data rely on reference genomes. Novel microbial communities extend far beyond the coverage of reference databases and de novo metagenome assembly from complex microbial communities remains a great challenge. Here we present a novel experimental and bioinformatic framework, metaSort, for effective construction of bacterial genomes from metagenomic samples. MetaSort provides a sorted mini-metagenome approach based on flow cytometry and single-cell sequencing methodologies, and employs new computational algorithms to efficiently recover high-quality genomes from the sorted mini-metagenome by the complementary of the original metagenome. Through extensive evaluations, we demonstrated that metaSort has an excellent and unbiased performance on genome recovery and assembly. Furthermore, we applied metaSort to an unexplored microflora colonized on the surface of marine kelp and successfully recovered 75 high-quality genomes at one time. This approach will greatly improve access to microbial genomes from complex or novel communities.
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Affiliation(s)
- Peifeng Ji
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanming Zhang
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinfeng Wang
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Fangqing Zhao
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
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104
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Shi B, Liang L, Yang H, Zhang L, He F. Glycerol-plasticized spirulina-poly(vinyl alcohol) films with improved mechanical performance. J Appl Polym Sci 2017. [DOI: 10.1002/app.44842] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Bo Shi
- Polymer Material Department, School of Chemical Engineering; Guangdong University of Petrochemical Technology; Maoming 525000 China
| | - Liang Liang
- Polymer Material Department, School of Chemical Engineering; Guangdong University of Petrochemical Technology; Maoming 525000 China
| | - Hui Yang
- Polymer Material Department, School of Chemistry and Chemical Engineering; Sun Yat-Sen University; Guangzhou 510006 China
| | - Liming Zhang
- Polymer Material Department, School of Chemistry and Chemical Engineering; Sun Yat-Sen University; Guangzhou 510006 China
| | - Fuan He
- Polymer Material Department, School of Chemical Engineering; Guangdong University of Petrochemical Technology; Maoming 525000 China
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105
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Morrison JM, Murphy CL, Baker K, Zamor RM, Nikolai SJ, Wilder S, Elshahed MS, Youssef NH. Microbial communities mediating algal detritus turnover under anaerobic conditions. PeerJ 2017; 5:e2803. [PMID: 28097050 PMCID: PMC5228501 DOI: 10.7717/peerj.2803] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 11/18/2016] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Algae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored. RESULTS Here, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta), Chara sp. strain IWP1 (Charophyceae), and kelp Ascophyllum nodosum (phylum Phaeophyceae), using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT), sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT), and deeper anoxic layers from a seasonally stratified lake (Grand Lake O' the Cherokees, OK; GL) as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13-16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes), Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate. Lineages enriched included the uncultured groups VadinBC27 and WCHB1-69 within the Bacteroidetes, genus Spirochaeta and the uncultured group SHA-4 within Spirochaetes, Ruminococcaceae, Lachnospiraceae, Yongiibacter, Geosporobacter, and Acidaminobacter within the Firmicutes, and genera Kluyvera, Pantoea, Edwardsiella and Aeromonas, and Buttiauxella within the Gamma-Proteobaceteria order Enterobacteriales. CONCLUSIONS Our results represent the first systematic survey of microbial communities mediating turnover of algal biomass under anaerobic conditions, and highlights the diversity of lineages putatively involved in the degradation process.
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Affiliation(s)
- Jessica M. Morrison
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Chelsea L. Murphy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Kristina Baker
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | | | | | - Shawn Wilder
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Mostafa S. Elshahed
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Noha H. Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
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106
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Wu C, Xiao Y, Lin W, Li J, Zhang S, Zhu J, Rong J. Aqueous enzymatic process for cell wall degradation and lipid extraction from Nannochloropsis sp. BIORESOURCE TECHNOLOGY 2017; 223:312-316. [PMID: 27806886 DOI: 10.1016/j.biortech.2016.10.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 10/19/2016] [Accepted: 10/20/2016] [Indexed: 05/13/2023]
Abstract
An effective cell disruption method, including alkaline pretreatment and subsequent enzymatic treatment, was established to break cell walls and extract lipid from Nannochloropsis sp. A synergistic effect was found between alkaline pretreatment and enzymatic treatment. The combination of commercialize enzymes (cellulase, protease, lysozyme, and pectinase) achieved higher lipid yield compared with a single enzyme application. With the compromise between economic feasibility and lipid yield, the optimum reaction conditions were obtained with alkaline pretreatment at pH 10.5 at 110°C for 4h, and subsequent enzymatic treatment at pH 4 at 50°C for 30min with the dosage of each enzyme at 200IU/g. As high as 90.0% of lipid was extracted under optimal conditions from Nannochloropsis sp.
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Affiliation(s)
- Chongchong Wu
- Department of Chemical and Petroleum Engineering, University of Calgary, T2N 1N4 Calgary, Alberta, Canada
| | - Ye Xiao
- Department of Chemical and Petroleum Engineering, University of Calgary, T2N 1N4 Calgary, Alberta, Canada
| | - Weiguo Lin
- Research Institute of Petroleum Processing, Sinopec, Beijing 100083, China
| | - Jiaquan Li
- Research Institute of Petroleum Processing, Sinopec, Beijing 100083, China
| | - Saisai Zhang
- Research Institute of Petroleum Processing, Sinopec, Beijing 100083, China
| | - Junying Zhu
- Research Institute of Petroleum Processing, Sinopec, Beijing 100083, China
| | - Junfeng Rong
- Research Institute of Petroleum Processing, Sinopec, Beijing 100083, China.
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107
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Lin CC, Yap CJS, Kan SC, Hsueh NC, Yang LY, Shieh CJ, Huang CC, Liu YC. Deciphering characteristics of the designer cellulosome from Bacillus subtilis WB800N via enzymatic analysis. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2016.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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108
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Liebetrau J, Sträuber H, Kretzschmar J, Denysenko V, Nelles M. Anaerobic Digestion. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 166:281-299. [PMID: 28391363 DOI: 10.1007/10_2016_67] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The term anaerobic digestion usually refers to the microbial conversion of organic material to biogas, which mainly consists of methane and carbon dioxide. The technical application of the naturally-occurring process is used to provide a renewable energy carrier and - as the substrate is often waste material - to reduce the organic matter content of the substrate prior to disposal.Applications can be found in sewage sludge treatment, the treatment of industrial and municipal solid wastes and wastewaters (including landfill gas utilization), and the conversion of agricultural residues and energy crops.For biorefinery concepts, the anaerobic digestion (AD) process is, on the one hand, an option to treat organic residues from other production processes. Concomitant effects are the reduction of organic carbon within the treated substance, the conversion of nitrogen and sulfur components, and the production of an energy-rich gas - the biogas. On the other hand, the multistep conversion of complex organic material offers the possibility of interrupting the conversion chain and locking out intermediates for utilization as basic material within the chemical industry.
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Affiliation(s)
- Jan Liebetrau
- Deutsches Biomasseforschungszentrum DBFZ, Leipzig, Germany.
| | - Heike Sträuber
- Helmholtz-Zentrum für Umweltforschung - UFZ, Leipzig, Germany
| | | | | | - Michael Nelles
- Deutsches Biomasseforschungszentrum DBFZ, Leipzig, Germany.,Universität Rostock, Rostock, Germany
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109
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Cano-Ramírez C, Santiago-Hernández A, Rivera-Orduña FN, García-Huante Y, Zúñiga G, Hidalgo-Lara ME. Expression, purification and characterization of an endoglucanase from Serratia proteamaculans CDBB-1961, isolated from the gut of Dendroctonus adjunctus (Coleoptera: Scolytinae). AMB Express 2016; 6:63. [PMID: 27576896 PMCID: PMC5005244 DOI: 10.1186/s13568-016-0233-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 08/18/2016] [Indexed: 12/02/2022] Open
Abstract
Serratia proteamaculans CDBB-1961, a gut symbiont from the roundheaded pine beetle Dendroctonus adjunctus, displayed strong cellulolytic activity on agar-plates with carboxymethyl cellulose (CMC) as carbon source. Automatic genome annotation of S. proteamaculans made possible the identification of a single endoglucanase encoding gene, designated spr cel8A. The predicted protein, named Spr Cel8A shows high similarity (59–94 %) to endo-1,4-β-d-glucanases (EC 3.2.1.4) from the glycoside hydrolase family 8 (GH8). The gene spr cel8A has an ORF of 1113 bp, encoding a 371 amino acid residue protein (41.2 kDa) with a signal peptide of 23 amino acid residues. Expression of the gene spr cel8A in Escherichia coli yields a mature recombinant endoglucanase 39 kDa. Cel8A displayed optimal activity at pH 7.0 and 40 °C, with a specific activity of 0.85 U/mg. The enzyme was stable at pH from 4 to 8.5, retaining nearly 40–80 % of its original activity, and exhibited a half-life of 8 days at 40 °C. The Km and Vmax values for Spr Cel8A were 6.87 mg/ml and 3.5 μmol/min/mg of protein, respectively, using CMC as substrate. The final principle products of Spr Cel8A-mediated hydrolysis of CMC were cellobiose, cello oligosaccharides and a small amount of glucose, suggesting that Spr Cel8A is an endo-β-1,4-glucanase manifesting exo-activity. This is the first report regarding the functional biochemical and molecular characterization of an endoglucanase from S. proteamaculans, found in the gut-associated bacteria community of Dendroctonus bark beetles. These results contribute to improved understanding of the functional role played by this bacterium as a symbiont of bark beetles.
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110
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Inamori T, Aburaya S, Morisaka H, Kuroda K, Ueda M. Characteristic strategy of assimilation of various saccharides by Clostridium cellulovorans. AMB Express 2016; 6:64. [PMID: 27586595 PMCID: PMC5009059 DOI: 10.1186/s13568-016-0237-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/24/2016] [Indexed: 11/10/2022] Open
Abstract
Clostridium cellulovorans can effectively assimilate not only cellulose but also hemicellulose by producing cellulosomal and non-cellulosomal enzymes. However, little is known about how C. cellulovorans assimilates various saccharides in media containing polysaccharides and oligosaccharides. In this research, we investigated the property of saccharide incorporation and assimilation by C. cellulovorans. Faster growth in media containing xylan and cellulose was achieved by switching polysaccharides, in which xylan was first assimilated, followed by cellulose. Furthermore, the presence of polysaccharides that can be easily degraded might increase the assimilation rate of lignocellulose by promoting growth. These properties of C. cellulovorans could be suitable for the effective utilization of lignocellulosic biomass.
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111
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Itoh T, Hibi T, Suzuki F, Sugimoto I, Fujiwara A, Inaka K, Tanaka H, Ohta K, Fujii Y, Taketo A, Kimoto H. Crystal Structure of Chitinase ChiW from Paenibacillus sp. str. FPU-7 Reveals a Novel Type of Bacterial Cell-Surface-Expressed Multi-Modular Enzyme Machinery. PLoS One 2016; 11:e0167310. [PMID: 27907169 PMCID: PMC5132251 DOI: 10.1371/journal.pone.0167310] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/13/2016] [Indexed: 12/03/2022] Open
Abstract
The Gram-positive bacterium Paenibacillus sp. str. FPU-7 effectively hydrolyzes chitin by using a number of chitinases. A unique chitinase with two catalytic domains, ChiW, is expressed on the cell surface of this bacterium and has high activity towards various chitins, even crystalline chitin. Here, the crystal structure of ChiW at 2.1 Å resolution is presented and describes how the enzyme degrades chitin on the bacterial cell surface. The crystal structure revealed a unique multi-modular architecture composed of six domains to function efficiently on the cell surface: a right-handed β-helix domain (carbohydrate-binding module family 54, CBM-54), a Gly-Ser-rich loop, 1st immunoglobulin-like (Ig-like) fold domain, 1st β/α-barrel catalytic domain (glycoside hydrolase family 18, GH-18), 2nd Ig-like fold domain and 2nd β/α-barrel catalytic domain (GH-18). The structure of the CBM-54, flexibly linked to the catalytic region of ChiW, is described here for the first time. It is similar to those of carbohydrate lyases but displayed no detectable carbohydrate degradation activities. The CBM-54 of ChiW bound to cell wall polysaccharides, such as chin, chitosan, β-1,3-glucan, xylan and cellulose. The structural and biochemical data obtained here also indicated that the enzyme has deep and short active site clefts with endo-acting character. The affinity of CBM-54 towards cell wall polysaccharides and the degradation pattern of the catalytic domains may help to efficiently decompose the cell wall chitin through the contact surface. Furthermore, we clarify that other Gram-positive bacteria possess similar cell-surface-expressed multi-modular enzymes for cell wall polysaccharide degradation.
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Affiliation(s)
- Takafumi Itoh
- Department of Bioscience, Fukui Prefectural University, Yoshida-gun, Fukui, Japan
- * E-mail: (TI); (HK)
| | - Takao Hibi
- Department of Bioscience, Fukui Prefectural University, Yoshida-gun, Fukui, Japan
| | - Fumiko Suzuki
- Department of Bioscience, Fukui Prefectural University, Yoshida-gun, Fukui, Japan
| | - Ikumi Sugimoto
- Department of Bioscience, Fukui Prefectural University, Yoshida-gun, Fukui, Japan
| | - Akihiro Fujiwara
- Department of Bioscience, Fukui Prefectural University, Yoshida-gun, Fukui, Japan
| | - Koji Inaka
- Maruwa Foods and Biosciences Inc., Yamatokoriyama, Nara, Japan
| | | | - Kazunori Ohta
- Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
| | - Yutaka Fujii
- Department of Molecular Biology and Chemistry, Faculty of Medicine, University of Fukui, Yoshida-gun, Fukui, Japan
| | - Akira Taketo
- Department of Environmental and Biotechnological Frontier Engineering, Fukui University of Technology, Fukui, Fukui, Japan
| | - Hisashi Kimoto
- Department of Bioscience, Fukui Prefectural University, Yoshida-gun, Fukui, Japan
- * E-mail: (TI); (HK)
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112
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Hyeon JE, Shin SK, Han SO. Design of nanoscale enzyme complexes based on various scaffolding materials for biomass conversion and immobilization. Biotechnol J 2016; 11:1386-1396. [PMID: 27783468 PMCID: PMC5132044 DOI: 10.1002/biot.201600039] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 09/26/2016] [Accepted: 10/07/2016] [Indexed: 12/14/2022]
Abstract
The utilization of scaffolds for enzyme immobilization involves advanced bionanotechnology applications in biorefinery fields, which can be achieved by optimizing the function of various enzymes. This review presents various current scaffolding techniques based on proteins, microbes and nanomaterials for enzyme immobilization, as well as the impact of these techniques on the biorefinery of lignocellulosic materials. Among them, architectural scaffolds have applied to useful strategies for protein engineering to improve the performance of immobilized enzymes in several industrial and research fields. In complexed enzyme systems that have critical roles in carbon metabolism, scaffolding proteins assemble different proteins in relatively durable configurations and facilitate collaborative protein interactions and functions. Additionally, a microbial strain, combined with designer enzyme complexes, can be applied to the immobilizing scaffold because the in vivo immobilizing technique has several benefits in enzymatic reaction systems related to both synthetic biology and metabolic engineering. Furthermore, with the advent of nanotechnology, nanomaterials possessing ideal physicochemical characteristics, such as mass transfer resistance, specific surface area and efficient enzyme loading, can be applied as novel and interesting scaffolds for enzyme immobilization. Intelligent application of various scaffolds to couple with nanoscale engineering tools and metabolic engineering technology may offer particular benefits in research.
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Affiliation(s)
- Jeong Eun Hyeon
- Department of BiotechnologyKorea University02841SeoulRepublic of Korea
| | - Sang Kyu Shin
- Department of BiotechnologyKorea University02841SeoulRepublic of Korea
| | - Sung Ok Han
- Department of BiotechnologyKorea University02841SeoulRepublic of Korea
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113
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Abstract
Complex carbohydrates are ubiquitous in all kingdoms of life. As major components of the plant cell wall they constitute both a rich renewable carbon source for biotechnological transformation into fuels, chemicals and materials, and also form an important energy source as part of a healthy human diet. In both contexts, there has been significant, sustained interest in understanding how microbes transform these substrates. Classical perspectives of microbial polysaccharide degradation are currently being augmented by recent advances in the discovery of lytic polysaccharide monooxygenases (LPMOs) and polysaccharide utilization loci (PULs). Fundamental discoveries in carbohydrate enzymology are both advancing biological understanding, as well as informing applications in industrial biomass conversion and modulation of the human gut microbiota to mediate health benefits.
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114
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Devendran S, Abdel-Hamid AM, Evans AF, Iakiviak M, Kwon IH, Mackie RI, Cann I. Multiple cellobiohydrolases and cellobiose phosphorylases cooperate in the ruminal bacterium Ruminococcus albus 8 to degrade cellooligosaccharides. Sci Rep 2016; 6:35342. [PMID: 27748409 PMCID: PMC5066209 DOI: 10.1038/srep35342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/28/2016] [Indexed: 12/01/2022] Open
Abstract
Digestion of plant cell wall polysaccharides is important in energy capture in the gastrointestinal tract of many herbivorous and omnivorous mammals, including humans and ruminants. The members of the genus Ruminococcus are found in both the ruminant and human gastrointestinal tract, where they show versatility in degrading both hemicellulose and cellulose. The available genome sequence of Ruminococcus albus 8, a common inhabitant of the cow rumen, alludes to a bacterium well-endowed with genes that target degradation of various plant cell wall components. The mechanisms by which R. albus 8 employs to degrade these recalcitrant materials are, however, not clearly understood. In this report, we demonstrate that R. albus 8 elaborates multiple cellobiohydrolases with multi-modular architectures that overall enhance the catalytic activity and versatility of the enzymes. Furthermore, our analyses show that two cellobiose phosphorylases encoded by R. albus 8 can function synergistically with a cognate cellobiohydrolase and endoglucanase to completely release, from a cellulosic substrate, glucose which can then be fermented by the bacterium for production of energy and cellular building blocks. We further use transcriptomic analysis to confirm the over-expression of the biochemically characterized enzymes during growth of the bacterium on cellulosic substrates compared to cellobiose.
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Affiliation(s)
- Saravanan Devendran
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ahmed M Abdel-Hamid
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Anton F Evans
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Michael Iakiviak
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - In Hyuk Kwon
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Roderick I Mackie
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Isaac Cann
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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115
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Chen B, Ma J, Xu Z, Wang X. Abscisic acid and ethephon regulation of cellulase in the endosperm cap and radicle during lettuce seed germination. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:859-869. [PMID: 27017965 DOI: 10.1111/jipb.12479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 03/22/2016] [Indexed: 05/09/2023]
Abstract
The purpose of this study was to investigate the role of cellulase in endosperm cap weakening and radicle elongation during lettuce (Lactuca sativa L.) seed germination. The application of abscisic acid (ABA) or ethephon inhibits or promotes germination, respectively, by affecting endosperm cap weakening and radicle elongation. Cellulase activities, and related protein and transcript abundances of two lettuce cellulase genes, LsCEL1 and LsCEL2, increase in the endosperm cap and radicle prior to radicle protrusion following imbibition in water. ABA or ethephon reduce or elevate, respectively, cellulase activity, and related protein and transcript abundances in the endosperm cap. Taken together, these observations suggest that cellulase plays a role in endosperm cap weakening and radicle elongation during lettuce seed germination, and that the regulation of cellulase in the endosperm cap by ABA and ethephon play a role in endosperm cap weakening. However, the influence of ABA and ethephon on radicle elongation may not be through their effects on cellulase.
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Affiliation(s)
- Bingxian Chen
- Seed Science and Technology Lab, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
- Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Jun Ma
- Seed Science and Technology Lab, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Zhenjiang Xu
- Seed Science and Technology Lab, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Xiaofeng Wang
- Seed Science and Technology Lab, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
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Li M, Yue Y, Zhang ZJ, Wang ZY, Tan TW, Fan LH. Site-Specific and High-Loading Immobilization of Proteins by Using Cohesin-Dockerin and CBM-Cellulose Interactions. Bioconjug Chem 2016; 27:1579-83. [PMID: 27357145 DOI: 10.1021/acs.bioconjchem.6b00282] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Immobilization of enzymes enhances their properties for application in industrial processes as reusable and robust biocatalysts. Here, we developed a new immobilization method by mimicking the natural cellulosome system. A group of cohesin and carbohydrate-binding module (CBM)-containing scaffoldins were genetically engineered, and their length was controlled by cohesin number. To use green fluorescent protein (GFP) as an immobilization model, its C-terminus was fused with a dockerin domain. GFP was able to specifically bind to scaffoldin via cohesin-dockerin interaction, while the scaffoldin could attach to cellulose by CBM-cellulose interaction. Our results showed that this mild and convenient approach was able to achieve site-specific immobilization, and the maximum GFP loading capacity reached ∼0.508 μmol/g cellulose.
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Affiliation(s)
- Mei Li
- Beijing Key Laboratory of Bioprocess. College of Life Science and Technology, Beijing University of Chemical Technology , Beisanhuan East Road #15, Beijing, China 100029
| | - Yi Yue
- Beijing Key Laboratory of Bioprocess. College of Life Science and Technology, Beijing University of Chemical Technology , Beisanhuan East Road #15, Beijing, China 100029
| | - Zi-Jian Zhang
- Beijing Key Laboratory of Bioprocess. College of Life Science and Technology, Beijing University of Chemical Technology , Beisanhuan East Road #15, Beijing, China 100029
| | - Zai-Yu Wang
- Beijing Key Laboratory of Bioprocess. College of Life Science and Technology, Beijing University of Chemical Technology , Beisanhuan East Road #15, Beijing, China 100029
| | - Tian-Wei Tan
- Beijing Key Laboratory of Bioprocess. College of Life Science and Technology, Beijing University of Chemical Technology , Beisanhuan East Road #15, Beijing, China 100029
| | - Li-Hai Fan
- Beijing Key Laboratory of Bioprocess. College of Life Science and Technology, Beijing University of Chemical Technology , Beisanhuan East Road #15, Beijing, China 100029
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Gunnoo M, Cazade PA, Galera-Prat A, Nash MA, Czjzek M, Cieplak M, Alvarez B, Aguilar M, Karpol A, Gaub H, Carrión-Vázquez M, Bayer EA, Thompson D. Nanoscale Engineering of Designer Cellulosomes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:5619-47. [PMID: 26748482 DOI: 10.1002/adma.201503948] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/01/2015] [Indexed: 05/27/2023]
Abstract
Biocatalysts showcase the upper limit obtainable for high-speed molecular processing and transformation. Efforts to engineer functionality in synthetic nanostructured materials are guided by the increasing knowledge of evolving architectures, which enable controlled molecular motion and precise molecular recognition. The cellulosome is a biological nanomachine, which, as a fundamental component of the plant-digestion machinery from bacterial cells, has a key potential role in the successful development of environmentally-friendly processes to produce biofuels and fine chemicals from the breakdown of biomass waste. Here, the progress toward so-called "designer cellulosomes", which provide an elegant alternative to enzyme cocktails for lignocellulose breakdown, is reviewed. Particular attention is paid to rational design via computational modeling coupled with nanoscale characterization and engineering tools. Remaining challenges and potential routes to industrial application are put forward.
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Affiliation(s)
- Melissabye Gunnoo
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Limerick, Ireland
| | - Pierre-André Cazade
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Limerick, Ireland
| | - Albert Galera-Prat
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), IMDEA Nanociencias and CIBERNED, Madrid, Spain
| | - Michael A Nash
- Lehrstuhl für Angewandte Physik and Center for Nanoscience, Ludwig-Maximilians-University, 80799, Munich, Germany
| | - Mirjam Czjzek
- Sorbonne Universités, UPMC, Université Paris 06, and Centre National de la Recherche Scientifique, UMR 8227, Integrative Biology of Marine Models, Station Biologique, de Roscoff, CS 90074, F-29688, Roscoff cedex, Bretagne, France
| | - Marek Cieplak
- Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | - Beatriz Alvarez
- Biopolis S.L., Parc Científic de la Universitat de Valencia, Edificio 2, C/Catedrático Agustín Escardino 9, 46980, Paterna (Valencia), Spain
| | - Marina Aguilar
- Abengoa, S.A., Palmas Altas, Calle Energía Solar nº 1, 41014, Seville, Spain
| | - Alon Karpol
- Designer Energy Ltd., 2 Bergman St., Tamar Science Park, Rehovot, 7670504, Israel
| | - Hermann Gaub
- Lehrstuhl für Angewandte Physik and Center for Nanoscience, Ludwig-Maximilians-University, 80799, Munich, Germany
| | - Mariano Carrión-Vázquez
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), IMDEA Nanociencias and CIBERNED, Madrid, Spain
| | - Edward A Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Damien Thompson
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Limerick, Ireland
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Applying functional metagenomics to search for novel lignocellulosic enzymes in a microbial consortium derived from a thermophilic composting phase of sugarcane bagasse and cow manure. Antonie van Leeuwenhoek 2016; 109:1217-33. [DOI: 10.1007/s10482-016-0723-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/07/2016] [Indexed: 10/21/2022]
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Singh G, Verma AK, Kumar V. Catalytic properties, functional attributes and industrial applications of β-glucosidases. 3 Biotech 2016; 6:3. [PMID: 28330074 PMCID: PMC4697909 DOI: 10.1007/s13205-015-0328-z] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/19/2015] [Indexed: 12/18/2022] Open
Abstract
β-Glucosidases are diverse group of enzymes with great functional importance to biological systems. These are grouped in multiple glycoside hydrolase families based on their catalytic and sequence characteristics. Most studies carried out on β-glucosidases are focused on their industrial applications rather than their endogenous function in the target organisms. β-Glucosidases performed many functions in bacteria as they are components of large complexes called cellulosomes and are responsible for the hydrolysis of short chain oligosaccharides and cellobiose. In plants, β-glucosidases are involved in processes like formation of required intermediates for cell wall lignification, degradation of endosperm’s cell wall during germination and in plant defense against biotic stresses. Mammalian β-glucosidases are thought to play roles in metabolism of glycolipids and dietary glucosides, and signaling functions. These enzymes have diverse biotechnological applications in food, surfactant, biofuel, and agricultural industries. The search for novel and improved β-glucosidase is still continued to fulfills demand of an industrially suitable enzyme. In this review, a comprehensive overview on detailed functional roles of β-glucosidases in different organisms, their industrial applications, and recent cloning and expression studies with biochemical characterization of such enzymes is presented for the better understanding and efficient use of diverse β-glucosidases.
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Affiliation(s)
- Gopal Singh
- Institute of Himalayan Bioresource Technology, Palampur, 176062, India
| | - A K Verma
- Department of Biochemistry, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, 263145, India
| | - Vinod Kumar
- Department of Biotechnology, Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, 173101, India.
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Chen X, Zhou M, Huang Z, Jia G, Liu G, Zhao H. Codon optimization of Aspergillus niger feruloyl esterase and its expression in Pichia pastoris. Biologia (Bratisl) 2016. [DOI: 10.1515/biolog-2016-0089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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121
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Bioprospecting for extracellular enzymes from culturable Actinobacteria from the South Shetland Islands, Antarctica. Polar Biol 2016. [DOI: 10.1007/s00300-016-1977-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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122
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Munir RI, Spicer V, Krokhin OV, Shamshurin D, Zhang X, Taillefer M, Blunt W, Cicek N, Sparling R, Levin DB. Transcriptomic and proteomic analyses of core metabolism in Clostridium termitidis CT1112 during growth on α-cellulose, xylan, cellobiose and xylose. BMC Microbiol 2016; 16:91. [PMID: 27215540 PMCID: PMC4877739 DOI: 10.1186/s12866-016-0711-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 05/16/2016] [Indexed: 01/15/2023] Open
Abstract
Background Clostridium termitidis CT1112 is an anaerobic, Gram-positive, mesophilic, spore-forming, cellulolytic bacterium, originally isolated from the gut of a wood feeding termite Nasusitermes lujae. It has the ability to hydrolyze both cellulose and hemicellulose, and ferment the degradation products to acetate, formate, ethanol, lactate, H2, and CO2. It is therefore ges in gene and gene product expression during growth of C. termitidis on cellobiose, xylose, xylan, and α–cellulose. Results Correlation of transcriptome and proteome data with growth and fermentation profiles identified putative carbon-catabolism pathways in C. termitidis. The majority of the proteins associated with central metabolism were detected in high abundance. While major differences were not observed in gene and gene-product expression for enzymes associated with metabolic pathways under the different substrate conditions, xylulokinase and xylose isomerase of the pentose phosphate pathway were found to be highly up-regulated on five carbon sugars compared to hexoses. In addition, genes and gene-products associated with a variety of cellulosome and non-cellulosome associated CAZymes were found to be differentially expressed. Specifically, genes for cellulosomal enzymes and components were highly expressed on α–cellulose, while xylanases and glucosidases were up-regulated on 5 carbon sugars with respect to cellobiose. Chitinase and cellobiophosphorylases were the predominant CAZymes expressed on cellobiose. In addition to growth on xylan, the simultaneous consumption of two important lignocellulose constituents, cellobiose and xylose was also demonstrated. Conclusion There are little changes in core-metabolic pathways under the different carbon sources compared. The most significant differences were found to be associated with the CAZymes, as well as specific up regulation of some key components of the pentose phosphate pathway in the presence of xylose and xylan. This study has enhanced our understanding of the physiology and metabolism of C. termitidis, and provides a foundation for future studies on metabolic engineering to optimize biofuel production from natural biomass. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0711-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Riffat I Munir
- Department of Biosystems Engineering, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Victor Spicer
- Department of Physics and Astronomy, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada.,Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Oleg V Krokhin
- Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Dmitry Shamshurin
- Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - XiangLi Zhang
- Department of Plant Science, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Marcel Taillefer
- Department of Microbiology, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Warren Blunt
- Department of Biosystems Engineering, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Nazim Cicek
- Department of Biosystems Engineering, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - Richard Sparling
- Department of Microbiology, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada
| | - David B Levin
- Department of Biosystems Engineering, University of Manitoba, R3T 5N6, Winnipeg, MB, Canada.
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Abstract
Extraction of sugar is the rate-limiting step in converting unpretreated biomass into value-added products through microbial fermentation. Both anaerobic fungi and anaerobic bacteria have evolved to produce large multi-cellulase complexes referred to as cellulosomes, which are powerful machines for biomass deconstruction. Characterization of bacterial cellulosomes has inspired synthetic "designer" cellulosomes, consisting of parts discovered from the native system that have proven useful for cellulose depolymerization. By contrast, the multi-cellulase complexes produced by anaerobic fungi are much more poorly understood, and to date their composition, architecture, and enzyme tethering mechanism remain unknown and heavily debated. Here, we compare current knowledge pertaining to the cellulosomes produced by both bacteria and fungi, including their application to synthetic enzyme-tethered systems for tunneled biocatalysis. We highlight gaps in knowledge and opportunities for discovery, especially pertaining to the potential of fungal cellulosome-inspired systems.
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Affiliation(s)
- Sean P Gilmore
- a Department of Chemical Engineering ; University of California ; Santa Barbara , CA USA
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124
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Karim Z, Afrin S, Husain Q, Danish R. Necessity of enzymatic hydrolysis for production and functionalization of nanocelluloses. Crit Rev Biotechnol 2016; 37:355-370. [PMID: 27049593 DOI: 10.3109/07388551.2016.1163322] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Nanocellulose (NC) from cellulosic biomass has recently gained attention owing to their biodegradable nature, low density, high mechanical properties, economic value and renewability. They still suffer, however, some drawbacks. The challenges are the exploration of raw materials, scaling, recovery of chemicals utilized for the production or functionalization and most important is toxic behavior that hinders them from implementing in medical/pharmaceutical field. This review emphasizes the structural behavior of cellulosic biomass and biological barriers for enzyme interactions, which are pertinent to understand the enzymatic hydrolysis of cellulose for the production of NCs. Additionally, the enzymatic catalysis for the modification of solid and NC is discussed. The utility of various classes of enzymes for introducing desired functional groups on the surface of NC has been further examined. Thereafter, a green mechanistic approach is applied for understanding at molecular level.
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Affiliation(s)
- Zoheb Karim
- a Division of Materials Science , Composite Centre Sweden, Luleå University of Technology , Luleå , Sweden
| | - Sadaf Afrin
- b Department of Chemistry, Faculty of Sciences , Aligarh Muslim University , Aligarh , UP , India
| | - Qayyum Husain
- c Department of Biochemistry, Faculty of Life Sciences , Aligarh Muslim University , Aligarh , UP , India
| | - Rehan Danish
- d Infinity Vacuum Technology , Geomdan Techpart Geomdangondan-Ro 26, Buk-Gu , Daegu , Korea
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Abstract
Designer cellulosomes consist of chimeric cohesin-bearing scaffoldins for the controlled incorporation of recombinant dockerin-containing enzymes. The largest designer cellulosome reported to date is a chimeric scaffoldin that contains 6 cohesins. This scaffoldin represented a technical limit of sorts, since adding another cohesin proved problematic, owing to resultant low expression levels, instability (cleavage) of the scaffoldin polypeptide, and limited numbers of available cohesin-dockerin specificities—the hallmark of designer cellulosomes. Nevertheless, increasing the number of enzymes integrated into designer cellulosomes is critical, in order to further enhance degradation of plant cell wall material. Adaptor scaffoldins comprise an intermediate type of scaffoldin that can both incorporate various enzymes and attach to an additional scaffoldin. Using this strategy, we constructed an efficient form of adaptor scaffoldin that possesses three type I cohesins for enzyme integration, a single type II dockerin for interaction with an additional scaffoldin, and a carbohydrate-binding module for targeting to the cellulosic substrate. In parallel, we designed a hexavalent scaffoldin capable of connecting to the adaptor scaffoldin by the incorporation of an appropriate type II cohesin. The resultant extended designer cellulosome comprised 8 recombinant enzymes—4 xylanases and 4 cellulases—thereby representing a potent enzymatic cocktail for solubilization of natural lignocellulosic substrates. The contribution of the adaptor scaffoldin clearly demonstrated that proximity between the two scaffoldins and their composite set of enzymes is crucial for optimized degradation. After 72 h of incubation, the performance of the extended designer cellulosome was determined to be approximately 70% compared to that of native cellulosomes. Plant cell wall residues represent a major source of renewable biomass for the production of biofuels such as ethanol via breakdown to soluble sugars. The natural microbial degradation process, however, is inefficient for achieving cost-effective processes in the conversion of plant-derived biomass to biofuels, either from dedicated crops or human-generated cellulosic wastes. The accumulation of the latter is considered a major environmental pollutant. The development of designer cellulosome nanodevices for enhanced plant cell wall degradation thus has major impacts in the fields of environmental pollution, bioenergy production, and biotechnology in general. The findings reported in this article comprise a true breakthrough in our capacity to produce extended designer cellulosomes via synthetic biology means, thus enabling the assembly of higher-order complexes that can supersede the number of enzymes included in a single multienzyme complex.
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126
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Artzi L, Morag E, Shamshoum M, Bayer EA. Cellulosomal expansin: functionality and incorporation into the complex. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:61. [PMID: 26973715 PMCID: PMC4788839 DOI: 10.1186/s13068-016-0474-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/02/2016] [Indexed: 05/24/2023]
Abstract
BACKGROUND Expansins are relatively small proteins that lack enzymatic activity and are found in plants and microorganisms. The function of these proteins is to disrupt the plant cell walls by interfering with the non-covalent interchain bonding of the polysaccharides. Expansins were found to be important for plant growth, but they are also expressed by various bacteria known to have interactions with plants. Clostridium clariflavum is a plant cell wall-degrading bacterium with a highly elaborate cellulosomal system. Among its numerous dockerin-containing genes, two expansin-like proteins, Clocl_1862 and Clocl_1298 (termed herein CclEXL1 and CclEXL2) were identified, and CclEXL1 was found to be expressed as part of the cellulosome system. This is the first time that an expansin-like protein is identified in a cellulosome complex, which implicates its possible role in biomass deconstruction. RESULTS In the present article, we analyzed the functionality of CclEXL1. Its dockerin was characterized and shown to bind selectively to type-I cohesins of C. clariflavum, with preferential binding to the cohesin of ScaG, and additionally to a type-I cohesin of C. cellulolyticum. We demonstrated experimentally that the expansin-like protein binds preferentially to microcrystalline cellulose, but it also binds to acid-swollen cellulose, xylan, and wheat straw. CclEXL1 exhibited a pronounced loosening effect on filter paper, which resulted in substantial decrease in tensile stress. The C. clariflavum expansin-like protein thus enhances significantly enzymatic hydrolysis of cellulose, both by C. clariflavum cellulosomes and two major cellulosomal cellulases from this bacterium: GH48 (exoglucanase) and GH9 (endoglucanase). Finally, we demonstrated CclEXL1-mediated enhancement of microcrystalline cellulose degradation by different cellulosome fractions and the two enzymes. CONCLUSIONS The results of this study confirm that the C. clariflavum expansin-like protein is part of the elaborate cellulosome system of this bacterium with capabilities of cellulose creeping. The data suggest that pretreatment of cellulosic materials with CclEXL1 can bring about substantial improvement of hydrolysis by cellulases.
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Affiliation(s)
- Lior Artzi
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Ely Morag
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Melina Shamshoum
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Edward A. Bayer
- Department of Molecular Biosciences, The Weizmann Institute of Science, Rehovot, Israel
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Hyeon JE, Kim SW, Park C, Han SO. Efficient biological conversion of carbon monoxide (CO) to carbon dioxide (CO2) and for utilization in bioplastic production by Ralstonia eutropha through the display of an enzyme complex on the cell surface. Chem Commun (Camb) 2016; 51:10202-5. [PMID: 26017299 DOI: 10.1039/c5cc00832h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An enzyme complex for biological conversion of CO to CO2 was anchored on the cell surface of the CO2-utilizing Ralstonia eutropha and successfully resulted in a 3.3-fold increase in conversion efficiency. These results suggest that this complexed system may be a promising strategy for CO2 utilization as a biological tool for the production of bioplastics.
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Affiliation(s)
- Jeong Eun Hyeon
- Department of Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
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128
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Sawhney N, Crooks C, Chow V, Preston JF, St John FJ. Genomic and transcriptomic analysis of carbohydrate utilization by Paenibacillus sp. JDR-2: systems for bioprocessing plant polysaccharides. BMC Genomics 2016; 17:131. [PMID: 26912334 PMCID: PMC4765114 DOI: 10.1186/s12864-016-2436-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/05/2016] [Indexed: 11/12/2022] Open
Abstract
Background Polysaccharides comprising plant biomass are potential resources for conversion to fuels and chemicals. These polysaccharides include xylans derived from the hemicellulose of hardwoods and grasses, soluble β-glucans from cereals and starch as the primary form of energy storage in plants. Paenibacillus sp. JDR-2 (Pjdr2) has evolved a system for bioprocessing xylans. The central component of this xylan utilization system is a multimodular glycoside hydrolase family 10 (GH10) endoxylanase with carbohydrate binding modules (CBM) for binding xylans and surface layer homology (SLH) domains for cell surface anchoring. These attributes allow efficient utilization of xylans by generating oligosaccharides proximal to the cell surface for rapid assimilation. Coordinate expression of genes in response to growth on xylans has identified regulons contributing to depolymerization, importation of oligosaccharides and intracellular processing to generate xylose as well as arabinose and methylglucuronate. The genome of Pjdr2 encodes several other putative surface anchored multimodular enzymes including those for utilization of β-1,3/1,4 mixed linkage soluble glucan and starch. Results To further define polysaccharide utilization systems in Pjdr2, its transcriptome has been determined by RNA sequencing following growth on barley-derived soluble β-glucan, starch, cellobiose, maltose, glucose, xylose and arabinose. The putative function of genes encoding transcriptional regulators, ABC transporters, and glycoside hydrolases belonging to the corresponding substrate responsive regulon were deduced by their coordinate expression and locations in the genome. These results are compared to observations from the previously defined xylan utilization systems in Pjdr2. The findings from this study show that Pjdr2 efficiently utilizes these glucans in a manner similar to xylans. From transcriptomic and genomic analyses we infer a common strategy evolved by Pjdr2 for efficient bioprocessing of polysaccharides. Conclusions The barley β-glucan and starch utilization systems in Pjdr2 include extracellular glycoside hydrolases bearing CBM and SLH domains for depolymerization of these polysaccharides. Overlapping regulation observed during growth on these polysaccharides suggests they are preferentially utilized in the order of starch before xylan before barley β-glucan. These systems defined in Pjdr2 may serve as a paradigm for developing biocatalysts for efficient bioprocessing of plant biomass to targeted biofuels and chemicals. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2436-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Neha Sawhney
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
| | - Casey Crooks
- Institute for Microbial and Biochemical Technology, Forest Products Laboratory, USDA Forest Service, Madison, WI, 53726, USA.
| | - Virginia Chow
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
| | - James F Preston
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
| | - Franz J St John
- Institute for Microbial and Biochemical Technology, Forest Products Laboratory, USDA Forest Service, Madison, WI, 53726, USA.
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Anderson CL, Schneider CJ, Erickson GE, MacDonald JC, Fernando SC. Rumen bacterial communities can be acclimated faster to high concentrate diets than currently implemented feedlot programs. J Appl Microbiol 2016; 120:588-99. [PMID: 26726754 PMCID: PMC4785609 DOI: 10.1111/jam.13039] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 12/09/2015] [Accepted: 12/19/2015] [Indexed: 11/29/2022]
Abstract
Aims Recent studies have demonstrated RAMP®, a complete starter feed, to have beneficial effects for animal performance. However, how RAMP may elicit such responses is unknown. To understand if RAMP adaptation results in changes in the rumen bacterial community that can potentially affect animal performance, we investigated the dynamics of rumen bacterial community composition in corn‐adapted and RAMP‐adapted cattle. Methods and Results During gradual acclimation of the rumen bacterial communities, we compared the bacterial community dynamics in corn and RAMP‐adapted using 16S rRNA gene amplicon sequencing. Significant shifts in bacterial populations across diets were identified. The shift in corn‐adapted animals occurred between adaptation step3 and step4, whereas in RAMP‐adapted cattle, the shift occurred between step2 and step3. As the adaptation program progressed, the abundance of OTUs associated with family Prevotellaceae and S24‐7 changed in corn‐adapted animals. In RAMP‐adapted animals, OTUs belonging to family Ruminococcaceae and Lachnospiraceae changed in abundance. Conclusions Rumen bacteria can be acclimated faster to high concentrate diets, such as RAMP, than traditional adaptation programs and the speed of bacterial community acclimation depends on substrate composition. Significance and Impact of the Study These findings may have implications for beef producers to reduce feedlot costs, as less time adapting animals would result in lower feed costs. However, animal feeding behavior patterns and other factors must be considered.
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Affiliation(s)
- C L Anderson
- School of Biological Science, University of Nebraska, Lincoln, NE, USA
| | - C J Schneider
- Department of Animal Science, University of Nebraska, Lincoln, NE, USA
| | - G E Erickson
- Department of Animal Science, University of Nebraska, Lincoln, NE, USA
| | - J C MacDonald
- Department of Animal Science, University of Nebraska, Lincoln, NE, USA
| | - S C Fernando
- Department of Animal Science, University of Nebraska, Lincoln, NE, USA
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130
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Xu Q, Resch MG, Podkaminer K, Yang S, Baker JO, Donohoe BS, Wilson C, Klingeman DM, Olson DG, Decker SR, Giannone RJ, Hettich RL, Brown SD, Lynd LR, Bayer EA, Himmel ME, Bomble YJ. Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities. SCIENCE ADVANCES 2016; 2:e1501254. [PMID: 26989779 PMCID: PMC4788478 DOI: 10.1126/sciadv.1501254] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/30/2015] [Indexed: 05/18/2023]
Abstract
Clostridium thermocellum is the most efficient microorganism for solubilizing lignocellulosic biomass known to date. Its high cellulose digestion capability is attributed to efficient cellulases consisting of both a free-enzyme system and a tethered cellulosomal system wherein carbohydrate active enzymes (CAZymes) are organized by primary and secondary scaffoldin proteins to generate large protein complexes attached to the bacterial cell wall. This study demonstrates that C. thermocellum also uses a type of cellulosomal system not bound to the bacterial cell wall, called the "cell-free" cellulosomal system. The cell-free cellulosome complex can be seen as a "long range cellulosome" because it can diffuse away from the cell and degrade polysaccharide substrates remotely from the bacterial cell. The contribution of these two types of cellulosomal systems in C. thermocellum was elucidated by characterization of mutants with different combinations of scaffoldin gene deletions. The primary scaffoldin, CipA, was found to play the most important role in cellulose degradation by C. thermocellum, whereas the secondary scaffoldins have less important roles. Additionally, the distinct and efficient mode of action of the C. thermocellum exoproteome, wherein the cellulosomes splay or divide biomass particles, changes when either the primary or secondary scaffolds are removed, showing that the intact wild-type cellulosomal system is necessary for this essential mode of action. This new transcriptional and proteomic evidence shows that a functional primary scaffoldin plays a more important role compared to secondary scaffoldins in the proper regulation of CAZyme genes, cellodextrin transport, and other cellular functions.
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Affiliation(s)
- Qi Xu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Michael G. Resch
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Kara Podkaminer
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Shihui Yang
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - John O. Baker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Charlotte Wilson
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Dawn M. Klingeman
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Daniel G. Olson
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Stephen R. Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Richard J. Giannone
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Robert L. Hettich
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Steven D. Brown
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Lee R. Lynd
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | | | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Corresponding author. E-mail:
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131
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Gaida SM, Liedtke A, Jentges AHW, Engels B, Jennewein S. Metabolic engineering of Clostridium cellulolyticum for the production of n-butanol from crystalline cellulose. Microb Cell Fact 2016; 15:6. [PMID: 26758196 PMCID: PMC4711022 DOI: 10.1186/s12934-015-0406-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/19/2015] [Indexed: 01/13/2023] Open
Abstract
Background Sustainable alternatives for the production of fuels and chemicals are needed to reduce our dependency on fossil resources and to avoid the negative impact of their excessive use on the global climate. Lignocellulosic feedstock from agricultural residues, energy crops and municipal solid waste provides an abundant and carbon-neutral alternative, but it is recalcitrant towards microbial degradation and must therefore undergo extensive pretreatment to release the monomeric sugar units used by biofuel-producing microbes. These pretreatment steps can be reduced by using microbes such as Clostridium cellulolyticum that naturally digest lignocellulose, but this limits the range of biofuels that can be produced. We therefore developed a metabolic engineering approach in C. cellulolyticum to expand its natural product spectrum and to fine tune the engineered metabolic pathways. Results Here we report the metabolic engineering of C. cellulolyticum to produce n-butanol, a next-generation biofuel and important chemical feedstock, directly from crystalline cellulose. We introduced the CoA-dependent pathway for n-butanol synthesis from C. acetobutylicum and measured the expression of functional enzymes (using targeted proteomics) and the abundance of metabolic intermediates (by LC-MS/MS) to identify potential bottlenecks in the n-butanol biosynthesis pathway. We achieved yields of 40 and 120 mg/L n-butanol from cellobiose and crystalline cellulose, respectively, after cultivating the bacteria for 6 and 20 days. Conclusion The analysis of enzyme activities and key intracellular metabolites provides a robust framework to determine the metabolic flux through heterologous pathways in C. cellulolyticum, allowing further improvements by fine tuning individual steps to improve the yields of n-butanol. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0406-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stefan Marcus Gaida
- Department of Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstrasse 6, 52074, Aachen, Germany.
| | - Andrea Liedtke
- Department of Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstrasse 6, 52074, Aachen, Germany.
| | - Andreas Heinz Wilhelm Jentges
- Department of Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstrasse 6, 52074, Aachen, Germany.
| | - Benedikt Engels
- Department of Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstrasse 6, 52074, Aachen, Germany.
| | - Stefan Jennewein
- Department of Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstrasse 6, 52074, Aachen, Germany.
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132
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Ullah MW, Khattak WA, Ul-Islam M, Khan S, Park JK. Metabolic engineering of synthetic cell-free systems: Strategies and applications. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2015.10.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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133
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Zhuang X, Wang W, Yu Q, Qi W, Wang Q, Tan X, Zhou G, Yuan Z. Liquid hot water pretreatment of lignocellulosic biomass for bioethanol production accompanying with high valuable products. BIORESOURCE TECHNOLOGY 2016; 199:68-75. [PMID: 26403722 DOI: 10.1016/j.biortech.2015.08.051] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 05/18/2023]
Abstract
Pretreatment is an essential prerequisite to overcome recalcitrance of biomass and enhance the ethanol conversion efficiency of polysaccharides. Compared with other pretreatment methods, liquid hot water (LHW) pretreatment not only reduces the downstream pressure by making cellulose more accessible to the enzymes but minimizes the formation of degradation products that inhibit the growth of fermentative microorganisms. Herein, this review summarized the improved LHW process for different biomass feedstocks, the decomposition behavior of biomass in the LHW process, the enzymatic hydrolysis of LHW-treated substrates, and production of high value-added products and ethanol. Moreover, a combined process producing ethanol and high value-added products was proposed basing on the works of Guangzhou Institute of Energy Conversion to make LHW pretreatment acceptable in the biorefinery of cellulosic ethanol.
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Affiliation(s)
- Xinshu Zhuang
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Wen Wang
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Qiang Yu
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Wei Qi
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Qiong Wang
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academic of Sciences, Beijing 100039, China
| | - Xuesong Tan
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Guixiong Zhou
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Zhenhong Yuan
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
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134
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Esaka K, Aburaya S, Morisaka H, Kuroda K, Ueda M. Exoproteome analysis of Clostridium cellulovorans in natural soft-biomass degradation. AMB Express 2015; 5:2. [PMID: 25642399 PMCID: PMC4305082 DOI: 10.1186/s13568-014-0089-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 12/23/2014] [Indexed: 02/03/2023] Open
Abstract
Clostridium cellulovorans is an anaerobic, cellulolytic bacterium, capable of effectively degrading various types of soft biomass. Its excellent capacity for degradation results from optimization of the composition of the protein complex (cellulosome) and production of non-cellulosomal proteins according to the type of substrates. In this study, we performed a quantitative proteome analysis to determine changes in the extracellular proteins produced by C. cellulovorans for degradation of several types of natural soft biomass. C. cellulovorans was cultured in media containing bagasse, corn germ, rice straw (natural soft biomass), or cellobiose (control). Using an isobaric tag method and a liquid chromatograph equipped with a long monolithic silica capillary column/mass spectrometer, we identified 372 proteins in the culture supernatant. Of these, we focused on 77 saccharification-related proteins of both cellulosomal and non-cellulosomal origins. Statistical analysis showed that 18 of the proteins were specifically produced during degradation of types of natural soft biomass. Interestingly, the protein Clocel_3197 was found and commonly involved in the degradation of every natural soft biomass studied. This protein may perform functions, in addition to its known metabolic functions, that contribute to effective degradation of natural soft biomass.
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135
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Toyofuku M, Tashiro Y, Hasegawa Y, Kurosawa M, Nomura N. Bacterial membrane vesicles, an overlooked environmental colloid: Biology, environmental perspectives and applications. Adv Colloid Interface Sci 2015; 226:65-77. [PMID: 26422802 DOI: 10.1016/j.cis.2015.08.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 08/27/2015] [Accepted: 08/27/2015] [Indexed: 12/31/2022]
Abstract
Phospholipid vesicles play important roles in biological systems. Bacteria are one of the most abundant organisms on Earth, and bacterial membrane vesicles (MVs) were first observed 50 years ago. Many bacteria release MVs to the environment that mainly consist of the cell membrane and typically range from 20 to 400 nm in size. Bacterial MVs are involved in several biological functions, such as delivery of cargo, virulence and gene transfer. MVs can be isolated from laboratory culture and directly from the environment, indicating their high abundance in and impact on ecosystems. Many colloidal particles in the environment ranging in size from 1 nm to 1 μm have been reported but not characterized at the molecular level, and MVs remain to be explored. Hence, MVs can be considered terra incognita in environmental colloid research. Although MV biogenesis and biological roles are yet to be fully understood, the accumulation of knowledge has opened new avenues for their applications. Via genetic engineering, the MV yield can be greatly increased, and the components of MVs can be tailored. Recent studies have demonstrated that MVs have promising potential for applications such as drug delivery systems and nanobiocatalysts. For instance, MV vaccines have been extensively studied and have already been approved in Europe. Recent MV studies have evoked great interest in the fields of biology and biotechnology, but fundamental questions, such as their transport in the environment or physicochemical features of MVs, remain to be addressed. In this review, we present the current understanding of bacterial MVs and environmental perspectives and further introduce their applications.
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Affiliation(s)
- Masanori Toyofuku
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Yosuke Tashiro
- Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University, Hamamatsu, Shizuoka 432-8561, Japan
| | - Yusuke Hasegawa
- Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University, Hamamatsu, Shizuoka 432-8561, Japan
| | - Masaharu Kurosawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Nobuhiko Nomura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
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136
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Raut MP, Karunakaran E, Mukherjee J, Biggs CA, Wright PC. Influence of Substrates on the Surface Characteristics and Membrane Proteome of Fibrobacter succinogenes S85. PLoS One 2015; 10:e0141197. [PMID: 26492413 PMCID: PMC4619616 DOI: 10.1371/journal.pone.0141197] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/06/2015] [Indexed: 12/02/2022] Open
Abstract
Although Fibrobacter succinogenes S85 is one of the most proficient cellulose degrading bacteria among all mesophilic organisms in the rumen of herbivores, the molecular mechanism behind cellulose degradation by this bacterium is not fully elucidated. Previous studies have indicated that cell surface proteins might play a role in adhesion to and subsequent degradation of cellulose in this bacterium. It has also been suggested that cellulose degradation machinery on the surface may be selectively expressed in response to the presence of cellulose. Based on the genome sequence, several models of cellulose degradation have been suggested. The aim of this study is to evaluate the role of the cell envelope proteins in adhesion to cellulose and to gain a better understanding of the subsequent cellulose degradation mechanism in this bacterium. Comparative analysis of the surface (exposed outer membrane) chemistry of the cells grown in glucose, acid-swollen cellulose and microcrystalline cellulose using physico-chemical characterisation techniques such as electrophoretic mobility analysis, microbial adhesion to hydrocarbons assay and Fourier transform infra-red spectroscopy, suggest that adhesion to cellulose is a consequence of an increase in protein display and a concomitant reduction in the cell surface polysaccharides in the presence of cellulose. In order to gain further understanding of the molecular mechanism of cellulose degradation in this bacterium, the cell envelope-associated proteins were enriched using affinity purification and identified by tandem mass spectrometry. In total, 185 cell envelope-associated proteins were confidently identified. Of these, 25 proteins are predicted to be involved in cellulose adhesion and degradation, and 43 proteins are involved in solute transport and energy generation. Our results supports the model that cellulose degradation in F. succinogenes occurs at the outer membrane with active transport of cellodextrins across for further metabolism of cellodextrins to glucose in the periplasmic space and inner cytoplasmic membrane.
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Affiliation(s)
- Mahendra P. Raut
- The ChELSI Institute, Dept of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
| | - Esther Karunakaran
- The ChELSI Institute, Dept of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
| | - Joy Mukherjee
- The ChELSI Institute, Dept of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
| | - Catherine A. Biggs
- The ChELSI Institute, Dept of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
| | - Phillip C. Wright
- The ChELSI Institute, Dept of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
- * E-mail:
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137
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Ichikawa S, Karita S. Bacterial production and secretion of water-insoluble fuel compounds from cellulose without the supplementation of cellulases. FEMS Microbiol Lett 2015; 362:fnv202. [DOI: 10.1093/femsle/fnv202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2015] [Indexed: 01/15/2023] Open
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138
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Tsai LC, Amiraslanov I, Chen HR, Chen YW, Lee HL, Liang PH, Liaw YC. Structures of exoglucanase from Clostridium cellulovorans: cellotetraose binding and cleavage. Acta Crystallogr F Struct Biol Commun 2015; 71:1264-72. [PMID: 26457517 PMCID: PMC4601590 DOI: 10.1107/s2053230x15015915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/25/2015] [Indexed: 11/10/2022] Open
Abstract
Exoglucanase/cellobiohydrolase (EC 3.2.1.176) hydrolyzes a β-1,4-glycosidic bond from the reducing end of cellulose and releases cellobiose as the major product. Three complex crystal structures of the glycosyl hydrolase 48 (GH48) cellobiohydrolase S (ExgS) from Clostridium cellulovorans with cellobiose, cellotetraose and triethylene glycol molecules were solved. The product cellobiose occupies subsites +1 and +2 in the open active-site cleft of the enzyme-cellotetraose complex structure, indicating an enzymatic hydrolysis function. Moreover, three triethylene glycol molecules and one pentaethylene glycol molecule are located at active-site subsites -2 to -6 in the structure of the ExgS-triethylene glycol complex shown here. Modelling of glucose into subsite -1 in the active site of the ExgS-cellobiose structure revealed that Glu50 acts as a proton donor and Asp222 plays a nucleophilic role.
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Affiliation(s)
- Li-Chu Tsai
- Molecular Science and Engineering, National Taipei University of Technology, 1, Section 3, Chung-Hsiao E. Road, Taipei 10608, Taiwan
| | - Imamaddin Amiraslanov
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Taipei 11529, Taiwan
| | - Hung-Ren Chen
- Molecular Science and Engineering, National Taipei University of Technology, 1, Section 3, Chung-Hsiao E. Road, Taipei 10608, Taiwan
| | - Yun-Wen Chen
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Taipei 11529, Taiwan
| | - Hsiao-Lin Lee
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Taipei 11529, Taiwan
| | - Po-Huang Liang
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Taipei 11529, Taiwan
| | - Yen-Chywan Liaw
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Taipei 11529, Taiwan
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139
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Petkun S, Rozman Grinberg I, Lamed R, Jindou S, Burstein T, Yaniv O, Shoham Y, Shimon LJ, Bayer EA, Frolow F. Reassembly and co-crystallization of a family 9 processive endoglucanase from its component parts: structural and functional significance of the intermodular linker. PeerJ 2015; 3:e1126. [PMID: 26401442 PMCID: PMC4579020 DOI: 10.7717/peerj.1126] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/04/2015] [Indexed: 11/22/2022] Open
Abstract
Non-cellulosomal processive endoglucanase 9I (Cel9I) from Clostridium thermocellum is a modular protein, consisting of a family-9 glycoside hydrolase (GH9) catalytic module and two family-3 carbohydrate-binding modules (CBM3c and CBM3b), separated by linker regions. GH9 does not show cellulase activity when expressed without CBM3c and CBM3b and the presence of the CBM3c was previously shown to be essential for endoglucanase activity. Physical reassociation of independently expressed GH9 and CBM3c modules (containing linker sequences) restored 60-70% of the intact Cel9I endocellulase activity. However, the mechanism responsible for recovery of activity remained unclear. In this work we independently expressed recombinant GH9 and CBM3c with and without their interconnecting linker in Escherichia coli. We crystallized and determined the molecular structure of the GH9/linker-CBM3c heterodimer at a resolution of 1.68 Å to understand the functional and structural importance of the mutual spatial orientation of the modules and the role of the interconnecting linker during their re-association. Enzyme activity assays and isothermal titration calorimetry were performed to study and compare the effect of the linker on the re-association. The results indicated that reassembly of the modules could also occur without the linker, albeit with only very low recovery of endoglucanase activity. We propose that the linker regions in the GH9/CBM3c endoglucanases are important for spatial organization and fixation of the modules into functional enzymes.
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Affiliation(s)
- Svetlana Petkun
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
| | - Inna Rozman Grinberg
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
| | - Sadanari Jindou
- Department of Life Sciences, Meijo University, Nagoya, Japan
| | - Tal Burstein
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
| | - Oren Yaniv
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Linda J.W. Shimon
- Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
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140
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Functional and structural properties of a novel cellulosome-like multienzyme complex: efficient glycoside hydrolysis of water-insoluble 7-xylosyl-10-deacetylpaclitaxel. Sci Rep 2015; 5:13768. [PMID: 26347949 PMCID: PMC4562250 DOI: 10.1038/srep13768] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 08/05/2015] [Indexed: 11/09/2022] Open
Abstract
Cellulosome is a kind of multienzyme complex that displays high activity, selectivity, and stability. Here, we report a novel, non-cellulolytic, cellulosome-like multienzyme complex that produced by the Cellulosimicrobium cellulans wild-type strain F16 isolated from soil microflora. This multienzyme complex, with excellent catalytic efficiency of kcat 13.2 s(-1) to remove the C-7 xylosyl group from 7-xylosyl-10-deacetylpaclitaxel (10-DAXP), has an outstanding tolerance against organic solvents and an excellent general stability, with the long half-life of 214 hours. This cellulosome-like multienzyme complex has a novel structure distinct from the well-documented ones. The key catalytic subunit responsible for the β-xylosidase activity against 10-DAXP is identified to be a novel protein, indicating a new glycoside hydrolase (GH) family. The pioneering work described here offers a novel nanoscale biocatalyst for the production of biofuels and chemicals from renewable plant-based natural resources.
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141
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Arora R, Behera S, Sharma NK, Kumar S. Bioprospecting thermostable cellulosomes for efficient biofuel production from lignocellulosic biomass. BIORESOUR BIOPROCESS 2015. [DOI: 10.1186/s40643-015-0066-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Rai KM, Balasubramanian VK, Welker CM, Pang M, Hii MM, Mendu V. Genome wide comprehensive analysis and web resource development on cell wall degrading enzymes from phyto-parasitic nematodes. BMC PLANT BIOLOGY 2015; 15:187. [PMID: 26232118 PMCID: PMC4521475 DOI: 10.1186/s12870-015-0576-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/16/2015] [Indexed: 05/08/2023]
Abstract
BACKGROUND The plant cell wall serves as a primary barrier against pathogen invasion. The success of a plant pathogen largely depends on its ability to overcome this barrier. During the infection process, plant parasitic nematodes secrete cell wall degrading enzymes (CWDEs) apart from piercing with their stylet, a sharp and hard mouthpart used for successful infection. CWDEs typically consist of cellulases, hemicellulases, and pectinases, which help the nematode to infect and establish the feeding structure or form a cyst. The study of nematode cell wall degrading enzymes not only enhance our understanding of the interaction between nematodes and their host, but also provides information on a novel source of enzymes for their potential use in biomass based biofuel/bioproduct industries. Although there is comprehensive information available on genome wide analysis of CWDEs for bacteria, fungi, termites and plants, but no comprehensive information available for plant pathogenic nematodes. Herein we have performed a genome wide analysis of CWDEs from the genome sequenced phyto pathogenic nematode species and developed a comprehensive publicly available database. RESULTS In the present study, we have performed a genome wide analysis for the presence of CWDEs from five plant parasitic nematode species with fully sequenced genomes covering three genera viz. Bursaphelenchus, Glorodera and Meloidogyne. Using the Hidden Markov Models (HMM) conserved domain profiles of the respective gene families, we have identified 530 genes encoding CWDEs that are distributed among 24 gene families of glycoside hydrolases (412) and polysaccharide lyases (118). Furthermore, expression profiles of these genes were analyzed across the life cycle of a potato cyst nematode. Most genes were found to have moderate to high expression from early to late infectious stages, while some clusters were invasion stage specific, indicating the role of these enzymes in the nematode's infection and establishment process. Additionally, we have also developed a Nematode's Plant Cell Wall Degrading Enzyme (NCWDE) database as a platform to provide a comprehensive outcome of the present study. CONCLUSIONS Our study provides collective information about different families of CWDEs from five different sequenced plant pathogenic nematode species. The outcomes of this study will help in developing better strategies to curtail the nematode infection, as well as help in identification of novel cell wall degrading enzymes for biofuel/bioproduct industries.
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Affiliation(s)
- Krishan Mohan Rai
- Department of Plant & Soil Science, Texas Tech University, 2802, 15th street, Lubbock, TX, 79409, USA.
| | | | - Cassie Marie Welker
- Department of Plant & Soil Science, Texas Tech University, 2802, 15th street, Lubbock, TX, 79409, USA.
| | - Mingxiong Pang
- Department of Plant & Soil Science, Texas Tech University, 2802, 15th street, Lubbock, TX, 79409, USA.
| | - Mei Mei Hii
- Department of Plant & Soil Science, Texas Tech University, 2802, 15th street, Lubbock, TX, 79409, USA.
- Current address Sarawak Biodiversity Centre, KM20, Jalan Borneo Heights, Semengoh, Locked Bag No. 3032, Kuching, Sarawak, 93990, Malaysia.
| | - Venugopal Mendu
- Department of Plant & Soil Science, Texas Tech University, 2802, 15th street, Lubbock, TX, 79409, USA.
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143
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Purification and Characterization of a Fucoidanase (FNase S) from a Marine Bacterium Sphingomonas paucimobilis PF-1. Mar Drugs 2015; 13:4398-417. [PMID: 26193285 PMCID: PMC4515624 DOI: 10.3390/md13074398] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/01/2015] [Accepted: 07/06/2015] [Indexed: 11/17/2022] Open
Abstract
The Search for enzyme activities that efficiently degrade marine polysaccharides is becoming an increasingly important area for both structural analysis and production of lower-molecular weight oligosaccharides. In this study, an endo-acting fucoidanase that degrades Miyeokgui fucoidan (MF), a sulfated galactofucan isolated from the sporophyll (called Miyeokgui in Korean) of Undaria pinnatifida, into smaller-sized galactofuco-oligosaccharides (1000-4000 Da) was purified from a marine bacterium, Sphingomonas paucimobilis PF-1, by ammonium sulfate precipitation, diethylaminoethyl (DEAE)-Sepharose column chromatography, and chromatofocusing. The specific activity of this enzyme was approximately 112-fold higher than that of the crude enzyme, and its molecular weight was approximately 130 kDa (FNase S), as determined by native gel electrophoresis and 130 (S1), 70 (S2) and 60 (S3) kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of FNase S were pH 6.0-7.0 and 40-45 °C, respectively. FNase S activity was enhanced by Mn2+ and Na+ (115.7% and 131.2%), but it was inhibited by Ca2+, K+, Ba2+, Cu2+ (96%, 83.7%, 84.3%, and 89.3%, respectively), each at 1 mM. The Km, Vmax and Kcat values of FNase S on MF were 1.7 mM, 0.62 mg·min-1, and 0.38·S-1, respectively. This enzyme could be a valuable tool for the structural analysis of fucoidans and production of bioactive fuco-oligosaccharides.
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144
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Tanaka T, Kondo A. Cell surface engineering of industrial microorganisms for biorefining applications. Biotechnol Adv 2015; 33:1403-11. [PMID: 26070720 DOI: 10.1016/j.biotechadv.2015.06.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 06/04/2015] [Accepted: 06/06/2015] [Indexed: 11/19/2022]
Abstract
In order to decrease carbon emissions and negative environmental impacts of various pollutants, biofuel/biochemical production should be promoted for replacing fossil-based industrial processes. Utilization of abundant lignocellulosic biomass as a feedstock has recently become an attractive option. In this review, we focus on recent efforts of cell surface display using industrial microorganisms such as Escherichia coli and yeast. Cell surface display is used primarily for endowing cellulolytic activity on the host cells, and enables direct fermentation to generate useful fuels and chemicals from lignocellulosic biomass. Cell surface display systems are systematically summarized, and the drawbacks/perspectives as well as successful application of surface display for industrial biotechnology are discussed.
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Affiliation(s)
- Tsutomu Tanaka
- Department of Chemical Science and Technology, Graduate School of Engineering, Kobe University, 1-1, Rokkodaicho, Nada, Kobe 657-8501 Japan
| | - Akihiko Kondo
- Department of Chemical Science and Technology, Graduate School of Engineering, Kobe University, 1-1, Rokkodaicho, Nada, Kobe 657-8501 Japan.
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145
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Abstract
Clostridium clariflavum is an anaerobic, cellulosome-forming thermophile, containing in its genome genes for a large number of cellulosomal enzyme and a complex scaffoldin system. Previously, we described the major cohesin-dockerin interactions of the cellulosome components, and on this basis a model of diverse cellulosome assemblies was derived. In this work, we cultivated C. clariflavum on cellobiose-, microcrystalline cellulose-, and switchgrass-containing media and isolated cell-free cellulosome complexes from each culture. Gel filtration separation of the cellulosome samples revealed two major fractions, which were analyzed by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to identify the key players of the cellulosome assemblies therein. From the 13 scaffoldins present in the C. clariflavum genome, 11 were identified, and a variety of enzymes from different glycoside hydrolase and carbohydrate esterase families were identified, including the glycoside hydrolase families GH48, GH9, GH5, GH30, GH11, and GH10. The expression level of the cellulosomal proteins varied as a function of the carbon source used for cultivation of the bacterium. In addition, the catalytic activity of each cellulosome was examined on different cellulosic substrates, xylan and switchgrass. The cellulosome isolated from the microcrystalline cellulose-containing medium was the most active of all the cellulosomes that were tested. The results suggest that the expression of the cellulosome proteins is regulated by the type of substrate in the growth medium. Moreover, both cell-free and cell-bound cellulosome complexes were produced which together may degrade the substrate in a synergistic manner. These observations are compatible with our previously published model of cellulosome assemblies in this bacterium. Because the reservoir of unsustainable fossil fuels, such as coal, petroleum, and natural gas, is overutilized and continues to contribute to environmental pollution and CO2 emission, the need for appropriate alternative energy sources becomes more crucial. Bioethanol produced from dedicated crops and cellulosic waste can provide a partial answer, yet a cost-effective production method must be developed. The cellulosome system of the anaerobic thermophile C. clariflavum comprises a large number of cellulolytic and hemicellulolytic enzymes, which self-assemble in a number of different cellulosome architectures for enhanced cellulosic biomass degradation. Identification of the major cellulosomal components expressed during growth of the bacterium and their influence on its catalytic capabilities provide insight into the performance of the remarkable cellulosome of this intriguing bacterium. The findings, together with the thermophilic characteristics of the proteins, render C. clariflavum of great interest for future use in industrial cellulose conversion processes.
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146
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Verma AK, Bule P, Ribeiro T, Brás JLA, Mukherjee J, Gupta MN, Fontes CMGA, Goyal A. The family 6 Carbohydrate Binding Module (CtCBM6) of glucuronoxylanase (CtXynGH30) of Clostridium thermocellum binds decorated and undecorated xylans through cleft A. Arch Biochem Biophys 2015; 575:8-21. [PMID: 25857803 DOI: 10.1016/j.abb.2015.03.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 02/24/2015] [Accepted: 03/17/2015] [Indexed: 10/23/2022]
Abstract
CtCBM6 of glucuronoxylan-xylanohydrolase (CtXynGH30) from Clostridium thermocellum was cloned, expressed and purified as a soluble ~14 kDa protein. Quantitative binding analysis with soluble polysaccharides by affinity electrophoresis and ITC revealed that CtCBM6 displays similar affinity towards decorated and undecorated xylans by binding wheat- and rye-arabinoxylans, beechwood-, birchwood- and oatspelt-xylan. Protein melting studies confirmed thermostable nature of CtCBM6 and that Ca(2+) ions did not affect its structure stability and binding affinity significantly. The CtCBM6 structure was modeled and refined and CD spectrum displayed 44% β-strands supporting the predicted structure. CtCBM6 displays a jelly roll β-sandwich fold presenting two potential carbohydrate binding clefts, A and B. The cleft A, is located between two loops connecting β4-β5 and β8-β9 strands. Tyr28 and Phe84 present on these loops make a planar hydrophobic binding surface to accommodate sugar ring of ligand. The cleft B, is located on concave surface of β-sandwich fold. Tyr34 and Tyr104 make a planar hydrophobic platform, which may be inaccessible to ligand due to hindrance by Pro68. Site-directed mutagenesis revealed Tyr28 and Phe84 in cleft A, playing a major role in ligand binding. The results suggest that CtCBM6 interacts with carbohydrates through cleft A, which recognizes equally well both decorated and un-decorated xylans.
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Affiliation(s)
- Anil Kumar Verma
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Pedro Bule
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Teresa Ribeiro
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Joana L A Brás
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Joyeeta Mukherjee
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Munishwar N Gupta
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Carlos M G A Fontes
- CIISA-Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Arun Goyal
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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147
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Baramee S, Phitsuwan P, Waeonukul R, Pason P, Tachaapaikoon C, Kosugi A, Ratanakhanokchai K. Alkaline xylanolytic–cellulolytic multienzyme complex from the novel anaerobic alkalithermophilic bacterium Cellulosibacter alkalithermophilus and its hydrolysis of insoluble polysaccharides under neutral and alkaline conditions. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.01.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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148
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An extracellular enzyme synthesizes narrow-sized silver nanoparticles in both water and methanol. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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149
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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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150
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Tanaka T, Kondo A. Cell-surface display of enzymes by the yeast Saccharomyces cerevisiae for synthetic biology. FEMS Yeast Res 2015; 15:1-9. [PMID: 25243459 DOI: 10.1111/1567-1364.12212] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/09/2014] [Accepted: 09/15/2014] [Indexed: 01/26/2023] Open
Abstract
In yeast cell-surface displays, functional proteins, such as cellulases, are genetically fused to an anchor protein and expressed on the cell surface. Saccharomyces cerevisiae, which is often utilized as a cell factory for the production of fuels, chemicals, and proteins, is the most commonly used yeast for cell-surface display. To construct yeast cells with a desired function, such as the ability to utilize cellulose as a substrate for bioethanol production, cell-surface display techniques for the efficient expression of enzymes on the cell membrane need to be combined with metabolic engineering approaches for manipulating target pathways within cells. In this Minireview, we summarize the recent progress of biorefinery fields in the development and application of yeast cell-surface displays from a synthetic biology perspective and discuss approaches for further enhancing cell-surface display efficiency.
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Affiliation(s)
- Tsutomu Tanaka
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Nada, Kobe, Japan
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