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Mandal A, Ahmed J, Singh S, Goyal A. Structure elucidation of a multi-modular recombinant endoglucanase, AtGH9C-CBM3A-CBM3B from Acetivibrio thermocellus ATCC 27405 and its substrate binding analysis. Int J Biol Macromol 2024; 273:133212. [PMID: 38897502 DOI: 10.1016/j.ijbiomac.2024.133212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/21/2024]
Abstract
Cellulases from GH9 family show endo-, exo- or processive endocellulase activity, but the reason behind the variation is unclear. A GH9 recombinant endoglucanase, AtGH9C-CBM3A-CBM3B from Acetivibrio thermocellus was structurally characterized for conformation, binding and dynamics assessment. Modeled AtGH9C-CBM3A-CBM3B depicted (α/α)6-barrel structure with Asp98, Asp101 and Glu489 acting as catalytic triad. CD results revealed 25.2 % α-helix, 18.4 % β-sheet and rest 56.4 % of random coils, corroborating with predictions from PSIPRED and SOPMA. MD simulation of AtGH9C-CBM3A-CBM3B bound cellotetraose showed structural stability and global compactness with lowered RMSD values (1.5 nm) as compared with only AtGH9C-CBM3A-CBM3B (1.8 nm) for 200 ns. Higher fluctuation in RMSF values in far-positioned CBM3B pointed to its redundancy in substrate binding. Docking studies showed maximum binding with cellotetraose (ΔG = -5.05 kcal/mol), with reduced affinity towards ligands with degree of polymerization (DP) lower (DP < 4) or higher than 4 (DP > 4). Processivity index displayed the enzyme to be processive with loop 3 (342-379 aa) possibly blocking the non-reducing end of cellulose chain, resulting in cellotetraose release. SAXS analysis of AtGH9C-CBM3A-CBM3B at 5 mg/mL displayed monodispersed state with fist-and-elbow shape in solution. Negative zeta potential of -24 mV at 5 mg/mL indicated stability and free from aggregation.
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Affiliation(s)
- Ardhendu Mandal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Jebin Ahmed
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Shweta Singh
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India; Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India.
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2
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Zajki-Zechmeister K, Eibinger M, Kaira GS, Nidetzky B. Mechanochemical Coupling of Catalysis and Motion in a Cellulose-Degrading Multienzyme Nanomachine. ACS Catal 2024; 14:2656-2663. [PMID: 38384941 PMCID: PMC10877591 DOI: 10.1021/acscatal.3c05653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/13/2024] [Accepted: 01/24/2024] [Indexed: 02/23/2024]
Abstract
The cellulosome is a megadalton-size protein complex that functions as a biological nanomachine of cellulosic fiber degradation. We show that the cellulosome behaves as a Brownian ratchet that rectifies protein motions on the cellulose surface into a propulsion mechanism by coupling to the hydrolysis of cellulose chains. Movement on cellulose fibrils is unidirectional and results from "macromolecular crawl" composed of dynamic switches between elongated and compact spatial arrangements of enzyme subunits. Deletion of the main exocellulase Cel48S eliminates conformational bias for aligning the subunits to the long fibril axis, which we reveal as crucial for optimum coupling between directional movement and substrate degradation. Implications of the cellulosome acting as a mechanochemical motor suggest a distinct mechanism of enzymatic machinery in the deconstruction of cellulose assemblies.
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Affiliation(s)
- Krisztina Zajki-Zechmeister
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, Graz 8010, Austria
| | - Manuel Eibinger
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, Graz 8010, Austria
| | - Gaurav Singh Kaira
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, Graz 8010, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, Graz 8010, Austria
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, Graz 8010, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, Graz 8010, Austria
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3
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Liu H, Zhang J, Zhang L, Zhang X, Yang R. Funneliformis mosseae influences leaf decomposition by altering microbial communities under saline-alkali conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:165079. [PMID: 37356763 DOI: 10.1016/j.scitotenv.2023.165079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/27/2023]
Abstract
Recent studies have indicated that arbuscular mycorrhizal fungi (AMF) can influence decomposition of organic materials. However, the underlying mechanisms remain unclear. Here we investigated whether AMF influence the decomposition of leaf litters and change the associated litter bacterial and fungal communities and whether this effect is altered by the level of soil saline-alkali. A pot experiment was conducted using Trifolium repens as host plant without or with AMF (Funneliformis mosseae) and with two levels of soil saline-alkali (0 and 200 mmol/L). Litterbags with different mesh size were used to measure the effect of AMF on decomposition. Our study found that AMF significantly accelerated leaf litter decomposition under both non-saline-alkali and saline-alkali conditions. The composition of bacterial and fungal communities was also altered by AMF independent of soil saline-alkali conditions. For bacterial community, AMF increased the richness but not the diversity and increased the relative abundance of Firmicutes and Nitrospirota. For fungal community, the richness and diversity were higher in AMF than in non-AMF treatment. AMF significantly resulted in a decrease of the relative abundance of Ascomycota but an increase of the relative abundance of Basidiomycota, Chytridiomycota, Mortierellomycota and Rozellomycota. Structural equation modeling (SEM) showed that AMF increased leaf litter decomposition under saline-alkali conditions primarily by affecting bacterial community composition. Together, we show that AMF increase decomposition and alter the bacterial and fungal communities, and that these effects are not modulated by the level of soil saline-alkali.
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Affiliation(s)
- Hui Liu
- College of Life Sciences, Dezhou University, Dezhou 253023, PR China.
| | - Jiazhen Zhang
- College of Life Sciences, Dezhou University, Dezhou 253023, PR China
| | - Luying Zhang
- College of Life Sciences, Dezhou University, Dezhou 253023, PR China
| | - Xi Zhang
- College of Life Sciences, Dezhou University, Dezhou 253023, PR China
| | - Rui Yang
- College of Life Sciences, Dezhou University, Dezhou 253023, PR China
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4
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Pandey S, Kim ES, Cho JH, Song M, Doo H, Kim S, Keum GB, Kwak J, Ryu S, Choi Y, Kang J, Lee JJ, Kim HB. Swine gut microbiome associated with non-digestible carbohydrate utilization. Front Vet Sci 2023; 10:1231072. [PMID: 37533451 PMCID: PMC10390834 DOI: 10.3389/fvets.2023.1231072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 07/04/2023] [Indexed: 08/04/2023] Open
Abstract
Non-digestible carbohydrates are an unavoidable component in a pig's diet, as all plant-based feeds contain different kinds of non-digestible carbohydrates. The major types of non-digestible carbohydrates include non-starch polysaccharides (such as cellulose, pectin, and hemicellulose), resistant starch, and non-digestible oligosaccharides (such as fructo-oligosaccharide and xylo-oligosaccharide). Non-digestible carbohydrates play a significant role in balancing the gut microbial ecology and overall health of the swine by promoting the production of short chain fatty acids. Although non-digestible carbohydrates are rich in energy, swine cannot extract this energy on their own due to the absence of enzymes required for their degradation. Instead, they rely on gut microbes to utilize these carbohydrates for energy production. Despite the importance of non-digestible carbohydrate degradation, limited studies have been conducted on the swine gut microbes involved in this process. While next-generation high-throughput sequencing has aided in understanding the microbial compositions of the swine gut, specific information regarding the bacteria involved in non-digestible carbohydrate degradation remains limited. Therefore, it is crucial to investigate and comprehend the bacteria responsible for the breakdown of non-digestible carbohydrates in the gut. In this mini review, we have discussed the major bacteria involved in the fermentation of different types of non-digestible carbohydrates in the large intestine of swine, shedding light on their potential roles and contributions to swine nutrition and health.
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Affiliation(s)
- Sriniwas Pandey
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Eun Sol Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Jin Ho Cho
- Division of Food and Animal Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Minho Song
- Division of Animal and Dairy Science, Chungnam National University, Daejeon, Republic of Korea
| | - Hyunok Doo
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Sheena Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Gi Beom Keum
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Jinok Kwak
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Sumin Ryu
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Yejin Choi
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Juyoun Kang
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Jeong Jae Lee
- Institute of Agricultural Science and Technology, Kyungpook National University, Daegu, Republic of Korea
| | - Hyeun Bum Kim
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
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de Camargo BR, Steindorff AS, da Silva LA, de Oliveira AS, Hamann PRV, Noronha EF. Expression profiling of Clostridium thermocellum B8 during the deconstruction of sugarcane bagasse and straw. World J Microbiol Biotechnol 2023; 39:105. [PMID: 36840776 DOI: 10.1007/s11274-023-03546-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/10/2023] [Indexed: 02/26/2023]
Abstract
The gram-positive bacterium Clostridium thermocellum contains a set of carbohydrate-active enzymes that can potentially be employed to generate high-value-added products from lignocellulose. In this study, the gene expression profiling of C. thermocellum B8 was provided during growth in the presence of sugarcane bagasse and straw as a carbon source in comparison to growth using microcrystalline cellulose. A total of 625 and 509 genes were up-regulated for growth in the presence of bagasse and straw, respectively. These genes were mainly grouped into carbohydrate-active enzymes (CAZymes), cell motility, chemotaxis, quorum sensing pathway and expression control of glycoside hydrolases. These results show that type of carbon source modulates the gene expression profiling of carbohydrate-active enzymes. In addition, highlight the importance of cell motility, attachment to the substrate and communication in deconstructing complex substrates. This present work may contribute to the development of enzymatic cocktails and industrial strains for biorefineries based on sugarcane residues as feedstock.
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Affiliation(s)
- Brenda Rabello de Camargo
- Laboratory of Enzymology, Department of Cell Biology, University of Brasília, Brasilia, DF, 70910-900, Brazil
| | | | - Leonardo Assis da Silva
- Laboratory of Virology, Department of Cell Biology, University of Brasília, Brasília, DF, Brazil
| | - Athos Silva de Oliveira
- Laboratory of Virology, Department of Cell Biology, University of Brasília, Brasília, DF, Brazil
| | - Pedro Ricardo Vieira Hamann
- São Carlos Institute of Physics, University of São Paulo, Avenida Trabalhador São-Carlense,400, Parque Arnold Schimidt, São Carlos, SP, 13566-590, Brazil
| | - Eliane Ferreira Noronha
- Laboratory of Enzymology, Department of Cell Biology, University of Brasília, Brasilia, DF, 70910-900, Brazil.
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6
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Zajki-Zechmeister K, Eibinger M, Nidetzky B. Enzyme Synergy in Transient Clusters of Endo- and Exocellulase Enables a Multilayer Mode of Processive Depolymerization of Cellulose. ACS Catal 2022; 12:10984-10994. [PMID: 36082050 PMCID: PMC9442579 DOI: 10.1021/acscatal.2c02377] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 08/12/2022] [Indexed: 11/29/2022]
Abstract
Biological degradation of cellulosic materials relies on the molecular-mechanistic principle that internally chain-cleaving endocellulases work synergistically with chain end-cleaving exocellulases in polysaccharide chain depolymerization. How endo-exo synergy becomes effective in the deconstruction of a solid substrate that presents cellulose chains assembled into crystalline material is an open question of the mechanism, with immediate implications on the bioconversion efficiency of cellulases. Here, based on single-molecule evidence from real-time atomic force microscopy, we discover that endo- and exocellulases engage in the formation of transient clusters of typically three to four enzymes at the cellulose surface. The clusters form specifically at regular domains of crystalline cellulose microfibrils that feature molecular defects in the polysaccharide chain organization. The dynamics of cluster formation correlates with substrate degradation through a multilayer-processive mode of chain depolymerization, overall leading to the directed ablation of single microfibrils from the cellulose surface. Each multilayer-processive step involves the spatiotemporally coordinated and mechanistically concerted activity of the endo- and exocellulases in close proximity. Mechanistically, the cooperativity with the endocellulase enables the exocellulase to pass through its processive cycles ∼100-fold faster than when acting alone. Our results suggest an advanced paradigm of efficient multienzymatic degradation of structurally organized polymer materials by endo-exo synergetic chain depolymerization.
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Affiliation(s)
- Krisztina Zajki-Zechmeister
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Manuel Eibinger
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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7
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Tatli M, Moraïs S, Tovar-Herrera OE, Bomble YJ, Bayer EA, Medalia O, Mizrahi I. Nanoscale resolution of microbial fiber degradation in action. eLife 2022; 11:76523. [PMID: 35638899 PMCID: PMC9191890 DOI: 10.7554/elife.76523] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/30/2022] [Indexed: 11/18/2022] Open
Abstract
The lives of microbes unfold at the micron scale, and their molecular machineries operate at the nanoscale. Their study at these resolutions is key toward achieving a better understanding of their ecology. We focus on cellulose degradation of the canonical Clostridium thermocellum system to comprehend how microbes build and use their cellulosomal machinery at these nanometer scales. Degradation of cellulose, the most abundant organic polymer on Earth, is instrumental to the global carbon cycle. We reveal that bacterial cells form ‘cellulosome capsules’ driven by catalytic product-dependent dynamics, which can increase the rate of hydrolysis. Biosynthesis of this energetically costly machinery and cell growth are decoupled at the single-cell level, hinting at a division-of-labor strategy through phenotypic heterogeneity. This novel observation highlights intrapopulation interactions as key to understanding rates of fiber degradation.
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Affiliation(s)
- Meltem Tatli
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Sarah Moraïs
- Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Omar E Tovar-Herrera
- Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | | | - Edward A Bayer
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Ohad Medalia
- Department of Biochemistry, University of Zürich, Zurich, Switzerland
| | - Itzhak Mizrahi
- Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
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8
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Patel DK, Menon DV, Patel DH, Dave G. Linkers: A synergistic way for the synthesis of chimeric proteins. Protein Expr Purif 2021; 191:106012. [PMID: 34767950 DOI: 10.1016/j.pep.2021.106012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/30/2021] [Accepted: 11/03/2021] [Indexed: 11/15/2022]
Abstract
In the cell, the protein domains are attached with the short oligopeptide, commonly known as linker peptide. Besides bridging, the linker assists in the domain-domain interaction and protein folding into the peculiar conformations. Linkers allow or control the movement of protein domains in the dynamic cellular environment. The recent advances in the recombinant DNA technology enable the construction of multiple gene constructs in an open reading frame. The express sequences can work in a cascade to cater for myriad functions. This trend has given momentum to incorporating bridge sequences (linker) that essentially separates the independent domains. According to the cellular need, the bridging partner can be spaced at a secure gap or requires attaching or interacting physically. The flexible or rigid linker can help to achieve such conformations in chimeric fusion proteins. The linker can improve solubility, proteolytic resistance and stability of such fusion proteins. Recently, linker aided protein switches and antibody-drug conjugates are gaining the attention of researchers worldwide. Here, we thoroughly reviewed the types of the linker, strategies for linker engineering and the composition of a linker.
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Affiliation(s)
- Dharti Keyur Patel
- PD Patel Institute of Applied Sciences, CHARUSAT, Changa, 388421, Gujarat, India
| | - Dhanya V Menon
- Tata Institute of Fundamental Research, NCBS, Bangalore, 560065, India
| | - Darshan H Patel
- Charotar Institute of Paramedical Sciences, CHARUSAT, Changa, 388421, Gujarat, India
| | - Gayatri Dave
- PD Patel Institute of Applied Sciences, CHARUSAT, Changa, 388421, Gujarat, India.
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9
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Zajki-Zechmeister K, Kaira GS, Eibinger M, Seelich K, Nidetzky B. Processive Enzymes Kept on a Leash: How Cellulase Activity in Multienzyme Complexes Directs Nanoscale Deconstruction of Cellulose. ACS Catal 2021; 11:13530-13542. [PMID: 34777910 PMCID: PMC8576811 DOI: 10.1021/acscatal.1c03465] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/11/2021] [Indexed: 12/15/2022]
Abstract
Biological deconstruction of polymer materials gains efficiency from the spatiotemporally coordinated action of enzymes with synergetic function in polymer chain depolymerization. To perpetuate enzyme synergy on a solid substrate undergoing deconstruction, the overall attack must alternate between focusing the individual enzymes locally and dissipating them again to other surface sites. Natural cellulases working as multienzyme complexes assembled on a scaffold protein (the cellulosome) maximize the effect of local concentration yet restrain the dispersion of individual enzymes. Here, with evidence from real-time atomic force microscopy to track nanoscale deconstruction of single cellulose fibers, we show that the cellulosome forces the fiber degradation into the transversal direction, to produce smaller fragments from multiple local attacks ("cuts"). Noncomplexed enzymes, as in fungal cellulases or obtained by dissociating the cellulosome, release the confining force so that fiber degradation proceeds laterally, observed as directed ablation of surface fibrils and leading to whole fiber "thinning". Processive cellulases that are enabled to freely disperse evoke the lateral degradation and determine its efficiency. Our results suggest that among natural cellulases, the dispersed enzymes are more generally and globally effective in depolymerization, while the cellulosome represents a specialized, fiber-fragmenting machinery.
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Affiliation(s)
- Krisztina Zajki-Zechmeister
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Gaurav Singh Kaira
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
| | - Manuel Eibinger
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Klara Seelich
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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10
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Kallscheuer N, Jogler C. The bacterial phylum Planctomycetes as novel source for bioactive small molecules. Biotechnol Adv 2021; 53:107818. [PMID: 34537319 DOI: 10.1016/j.biotechadv.2021.107818] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/21/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
Extensive knowledge and methodological expertise on the bacterial cell biology have been accumulated over the last decades and bacterial cells have now become an integral part of several (bio-)technological processes. While it appears reasonable to focus on a relatively small number of fast-growing and genetically easily manipulable model bacteria as biotechnological workhorses, the for the most part untapped diversity of bacteria needs to be explored when it comes to bioprospecting for natural product discovery. Members of the underexplored and evolutionarily deep-branching phylum Planctomycetes have only recently gained increased attention with respect to the production of small molecules with biomedical activities, e.g. as a natural source of novel antibiotics. Next-generation sequencing and metagenomics can provide access to the genomes of uncultivated bacteria from sparsely studied phyla, this, however, should be regarded as an addition rather than a substitute for classical strain isolation approaches. Ten years ago, a large sampling campaign was initiated to isolate planctomycetes from their varied natural habitats and protocols were developed to address complications during cultivation of representative species in the laboratory. The characterisation of approximately 90 novel strains by several research groups in the recent years opened a detailed in silico look into the coding potential of individual members of this phylum. Here, we review the current state of planctomycetal research, focusing on diversity, small molecule production and potential future applications. Although the field developed promising, the time frame of 10 years illustrates that the study of additional promising bacterial phyla as sources for novel small molecules needs to start rather today than tomorrow.
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Affiliation(s)
- Nicolai Kallscheuer
- Institute of Bio- and Geosciences (IBG-1): Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany; Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Christian Jogler
- Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany.
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11
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Hershko Rimon A, Livnah O, Rozman Grinberg I, Ortiz de Ora L, Yaniv O, Lamed R, Bayer EA, Frolow F, Voronov-Goldman M. Novel clostridial cell-surface hemicellulose-binding CBM3 proteins. Acta Crystallogr F Struct Biol Commun 2021; 77:95-104. [PMID: 33830074 PMCID: PMC8034430 DOI: 10.1107/s2053230x21002764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 03/15/2021] [Indexed: 11/10/2022] Open
Abstract
A novel member of the family 3 carbohydrate-binding modules (CBM3s) is encoded by a gene (Cthe_0271) in Clostridium thermocellum which is the most highly expressed gene in the bacterium during its growth on several types of biomass substrates. Surprisingly, CtCBM3-0271 binds to at least two different types of xylan, instead of the common binding of CBM3s to cellulosic substrates. CtCBM3-0271 was crystallized and its three-dimensional structure was solved and refined to a resolution of 1.8 Å. In order to learn more about the role of this type of CBM3, a comparative study with its orthologue from Clostridium clariflavum (encoded by the Clocl_1192 gene) was performed, and the three-dimensional structure of CcCBM3-1192 was determined to 1.6 Å resolution. Carbohydrate binding by CcCBM3-1192 was found to be similar to that by CtCBM3-0271; both exhibited binding to xylan rather than to cellulose. Comparative structural analysis of the two CBM3s provided a clear functional correlation of structure and binding, in which the two CBM3s lack the required number of binding residues in their cellulose-binding strips and thus lack cellulose-binding capabilities. This is an enigma, as CtCBM3-0271 was reported to be a highly expressed protein when the bacterium was grown on cellulose. An additional unexpected finding was that CcCBM3-1192 does not contain the calcium ion that was considered to play a structural stabilizing role in the CBM3 family. Despite the lack of calcium, the five residues that form the calcium-binding site are conserved. The absence of calcium results in conformational changes in two loops of the CcCBM3-1192 structure. In this context, superposition of the non-calcium-binding CcCBM3-1192 with CtCBM3-0271 and other calcium-binding CBM3s reveals a much broader two-loop region in the former compared with CtCBM3-0271.
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Affiliation(s)
- Almog Hershko Rimon
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Oded Livnah
- The Wolfson Center for Applied and Structural Biology, Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Inna Rozman Grinberg
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology Research, Tel Aviv University, Ramat Aviv 69978, Israel
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Lizett Ortiz de Ora
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
- Department of Chemistry, University of California, Irvine, CA 92697, USA
| | - Oren Yaniv
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Raphael Lamed
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 760001, Israel
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8499000, Israel
| | - Felix Frolow
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Milana Voronov-Goldman
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology Research, Tel Aviv University, Ramat Aviv 69978, Israel
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12
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Bacterial valorization of pulp and paper industry process streams and waste. Appl Microbiol Biotechnol 2021; 105:1345-1363. [PMID: 33481067 DOI: 10.1007/s00253-021-11107-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/28/2020] [Accepted: 01/08/2021] [Indexed: 10/22/2022]
Abstract
The pulp and paper industry is a major source of lignocellulose-containing streams. The components of lignocellulose material are lignin, hemicellulose, and cellulose that may be hydrolyzed into their smaller components and used as feedstocks for valorization efforts. Much of this material is contained in underutilized streams and waste products, such as black liquor, pulp and paper sludge, and wastewater. Bacterial fermentation strategies have suitable potential to upgrade lignocellulosic biomass contained in these streams to value-added chemicals. Bacterial conversion allows for a sustainable and economically feasible approach to valorizing these streams, which can bolster and expand applications of the pulp and paper industry. This review discusses the composition of pulp and paper streams, bacterial isolates from process streams that can be used for lignocellulose biotransformations, and technological approaches for improving valorization efforts. KEY POINTS: • Reviews the conversion of pulp and paper industry waste by bacterial isolates. • Metabolic pathways for the breakdown of lignocellulose components. • Methods for isolating bacteria, determining value-added products, and increasing product yields.
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13
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Ghosh S, Godoy L, Anchang KY, Achilonu CC, Gryzenhout M. Fungal Cellulases: Current Research and Future Challenges. Fungal Biol 2021. [DOI: 10.1007/978-3-030-85603-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Zafar A, Aftab MN, Asif A, Karadag A, Peng L, Celebioglu HU, Afzal MS, Hamid A, Iqbal I. Efficient biomass saccharification using a novel cellobiohydrolase from Clostridium clariflavum for utilization in biofuel industry. RSC Adv 2021; 11:9246-9261. [PMID: 35423428 PMCID: PMC8695235 DOI: 10.1039/d1ra00545f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/18/2021] [Accepted: 02/23/2021] [Indexed: 11/30/2022] Open
Abstract
The present study describes the cloning of the cellobiohydrolase gene from a thermophilic bacterium Clostridium clariflavum and its expression in Escherichia coli BL21(DE3) utilizing the expression vector pET-21a(+). The optimization of various parameters (pH, temperature, isopropyl β-d-1-thiogalactopyranoside (IPTG) concentration, time of induction) was carried out to obtain the maximum enzyme activity (2.78 ± 0.145 U ml−1) of recombinant enzyme. The maximum expression of recombinant cellobiohydrolase was obtained at pH 6.0 and 70 °C respectively. Enzyme purification was performed by heat treatment and immobilized metal anionic chromatography. The specific activity of the purified enzyme was 57.4 U mg−1 with 35.17% recovery and 3.90 purification fold. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight of cellobiohydrolase was 78 kDa. Among metal ions, Ca2+ showed a positive impact on the cellobiohydrolase enzyme with increased activity by 115%. Recombinant purified cellobiohydrolase enzyme remained stable and exhibited 77% and 63% residual activity in comparison to control in the presence of n-butanol and after incubation at 80 °C for 1 h, respectively. Our results indicate that our purified recombinant cellobiohydrolase can be used in the biofuel industry. Successful expression of a novel cellobiohydrolase enzyme from Clostridium clariflavum with efficient saccharification potential of plant biomass for the biofuel industry.![]()
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Affiliation(s)
- Asma Zafar
- Faculty of Life Sciences
- University of Central Punjab
- Lahore
- Pakistan
| | | | - Anam Asif
- Institute of Industrial Biotechnology
- GC University
- Lahore
- Pakistan
| | - Ahmet Karadag
- Department of Chemistry
- Faculty of Arts and Sciences
- Yozgat Bozok University
- Yozgat
- Turkey
| | - Liangcai Peng
- Biomass and Bioenergy Research Center
- Huazhong Agriculture University
- Wuhan
- China
| | | | - Muhammad Sohail Afzal
- Department of Life Sciences
- School of Science
- University of Management and Technology (UMT)
- Lahore
- Pakistan
| | - Attia Hamid
- Institute of Industrial Biotechnology
- GC University
- Lahore
- Pakistan
| | - Irfana Iqbal
- Department of Zoology
- Lahore College for Women University
- Lahore
- Pakistan
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15
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Kyu MT, Nishio S, Noda K, Dar B, Aye SS, Matsuda T. Predominant secretion of cellobiohydrolases and endo-β-1,4-glucanases in nutrient-limited medium by Aspergillus spp. isolated from subtropical field. J Biochem 2020; 168:243-256. [DOI: 10.1093/jb/mvaa049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/29/2020] [Indexed: 01/03/2023] Open
Abstract
Abstract
Biological degradation of cellulose from dead plants in nature and plant biomass from agricultural and food-industry waste is important for sustainable carbon recirculation. This study aimed at searching diverse cellulose-degrading systems of wild filamentous fungi and obtaining fungal lines useful for cellooligosaccharide production from agro-industrial wastes. Fungal lines with cellulolytic activity were screened and isolated from stacked rice straw and soil in subtropical fields. Among 13 isolated lines, in liquid culture with a nutrition-limited cellulose-containing medium, four lines of Aspergillus spp. secreted 50–60 kDa proteins as markedly dominant components and gave clear activity bands of possible endo-β-1,4-glucanase in zymography. Mass spectroscopy (MS) analysis of the dominant components identified three endo-β-1,4-glucanases (GH5, GH7 and GH12) and two cellobiohydrolases (GH6 and GH7). Cellulose degradation by the secreted proteins was analysed by LC-MS-based measurement of derivatized reducing sugars. The enzymes from the four Aspergillus spp. produced cellobiose from crystalline cellulose and cellotriose at a low level compared with cellobiose. Moreover, though smaller than that from crystalline cellulose, the enzymes of two representative lines degraded powdered rice straw and produced cellobiose. These fungal lines and enzymes would be effective for production of cellooligosaccharides as cellulose degradation-intermediates with added value other than glucose.
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Affiliation(s)
- May Thin Kyu
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
- Department of Botany, University of Yangon, University Avenue Road, Kamayut Township 11041, Yangon, Myanmar
| | - Shunsuke Nishio
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Koki Noda
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Bay Dar
- Department of Botany, University of Yangon, University Avenue Road, Kamayut Township 11041, Yangon, Myanmar
| | - San San Aye
- Department of Botany, University of Yangon, University Avenue Road, Kamayut Township 11041, Yangon, Myanmar
| | - Tsukasa Matsuda
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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16
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Jiang N, Ma XD, Fu LH, Li CX, Feng JX, Duan CJ. Identification of a unique 1,4-β-D-glucan glucohydrolase of glycoside hydrolase family 9 from Cytophaga hutchinsonii. Appl Microbiol Biotechnol 2020; 104:7051-7066. [PMID: 32577801 DOI: 10.1007/s00253-020-10731-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 05/25/2020] [Accepted: 06/07/2020] [Indexed: 10/24/2022]
Abstract
Cytophaga hutchinsonii is an aerobic cellulolytic soil bacterium that rapidly digests crystalline cellulose. The predicted mechanism by which C. hutchinsonii digests cellulose differs from that of other known cellulolytic bacteria and fungi. The genome of C. hutchinsonii contains 22 glycoside hydrolase (GH) genes, which may be involved in cellulose degradation. One predicted GH with uncertain specificity, CHU_0961, is a modular enzyme with several modules. In this study, phylogenetic tree of the catalytic modules of the GH9 enzymes showed that CHU_0961 and its homologues formed a new group (group C) of GH9 enzymes. The catalytic module of CHU_0961 (CHU_0961B) was identified as a 1,4-β-D-glucan glucohydrolase (EC 3.2.1.74) that has unique properties compared with known GH9 cellulases. CHU_0961B showed highest activity against barley glucan, but low activity against other polysaccharides. Interestingly, CHU_0961B showed similar activity against ρ-nitrophenyl β-D-cellobioside (ρ-NPC) and ρ-nitrophenyl β-D-glucopyranoside. CHU_0961B released glucose from the nonreducing end of cello-oligosaccharides, ρ-NPC, and barley glucan in a nonprocessive exo-type mode. CHU_0961B also showed same hydrolysis mode against deacetyl-chitooligosaccharides as against cello-oligosaccharides. The kcat/Km values for CHU_0961B against cello-oligosaccharides increased as the degree of polymerization increased, and its kcat/Km for cellohexose was 750 times higher than that for cellobiose. Site-directed mutagenesis showed that threonine 321 in CHU_0961 played a role in hydrolyzing cellobiose to glucose. CHU_0961 may act synergistically with other cellulases to convert cellulose to glucose on the bacterial cell surface. The end product, glucose, may initiate cellulose degradation to provide nutrients for bacterial proliferation in the early stage of C. hutchinsonii growth. KEY POINTS: • CHU_0961 and its homologues formed a novel group (group C) of GH9 enzymes. • CHU_0961 was identified as a 1,4-β-d-glucan glucohydrolase with unique properties. • CHU_0961 may play an important role in the early stage of C. hutchinsonii growth.
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Affiliation(s)
- Nan Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Xiao-Dan Ma
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Li-Hao Fu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Cheng-Xi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Cheng-Jie Duan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China.
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17
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Eibinger M, Ganner T, Plank H, Nidetzky B. A Biological Nanomachine at Work: Watching the Cellulosome Degrade Crystalline Cellulose. ACS CENTRAL SCIENCE 2020; 6:739-746. [PMID: 32490190 PMCID: PMC7256933 DOI: 10.1021/acscentsci.0c00050] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Indexed: 05/14/2023]
Abstract
The cellulosome is a supramolecular multienzymatic protein complex that functions as a biological nanomachine of cellulosic biomass degradation. How the megadalton-size cellulosome adapts to a solid substrate is central to its mechanism of action and is also key for its efficient use in bioconversion applications. We report time-lapse visualization of crystalline cellulose degradation by individual cellulosomes from Clostridium thermocellum by atomic force microscopy. Upon binding to cellulose, the cellulosomes switch to elongated, even filamentous shapes and morph these dynamically at below 1 min time scale according to requirements of the substrate surface under attack. Compared with noncomplexed cellulases that peel off material while sliding along crystalline cellulose surfaces, the cellulosomes remain bound locally for minutes and remove the material lying underneath. The consequent roughening up of the surface leads to an efficient deconstruction of cellulose nanocrystals both from the ends and through fissions within. Distinct modes of cellulose nanocrystal deconstruction by nature's major cellulase systems are thus revealed.
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Affiliation(s)
- Manuel Eibinger
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Thomas Ganner
- Institute
for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Harald Plank
- Institute
for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
- Graz
Centre of Electron Microscopy, Steyrergasse 17, A-8010 Graz, Austria
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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18
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McConnell SA, Cannon KA, Morgan C, McAllister R, Amer BR, Clubb RT, Yeates TO. Designed Protein Cages as Scaffolds for Building Multienzyme Materials. ACS Synth Biol 2020; 9:381-391. [PMID: 31922719 DOI: 10.1021/acssynbio.9b00407] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The functions of enzymes can be strongly affected by their higher-order spatial arrangements. In this study we combine multiple new technologies-designer protein cages and sortase-based enzymatic attachments between proteins-as a novel platform for organizing multiple enzymes (of one or more types) in specified configurations. As a scaffold we employ a previously characterized 24-subunit designed protein cage whose termini are outwardly exposed for attachment. As a first-use case, we test the attachment of two cellulase enzymes known to act synergistically in cellulose degradation. We show that, after endowing the termini of the cage subunits with a short "sort-tag" sequence (LPXTG) and the opposing termini of the cellulase enzymes with a short polyglycine sequence tag, addition of sortase covalently attaches the enzymes to the cage with good reactivity and high copy number. The doubly modified cages show enhanced activity in a cellulose degradation assay compared to enzymes in solution, and compared to a combination of singly modified cages. These new engineering strategies could be broadly useful in the development of enzymatic material and synthetic biology applications.
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Affiliation(s)
- Scott A. McConnell
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Molecular Biology Institute, University of California, Los Angeles, California 90095, United States
| | - Kevin A. Cannon
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Christian Morgan
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095, United States
| | - Rachel McAllister
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Brendan R. Amer
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Molecular Biology Institute, University of California, Los Angeles, California 90095, United States
| | - Robert T. Clubb
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Molecular Biology Institute, University of California, Los Angeles, California 90095, United States
| | - Todd O. Yeates
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Molecular Biology Institute, University of California, Los Angeles, California 90095, United States
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19
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Yu G, Liu S, Feng X, Zhang Y, Liu C, Liu YJ, Li B, Cui Q, Peng H. Impact of ammonium sulfite-based sequential pretreatment combinations on two distinct saccharifications of wheat straw. RSC Adv 2020; 10:17129-17142. [PMID: 35521439 PMCID: PMC9053470 DOI: 10.1039/d0ra01759k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/22/2020] [Indexed: 01/27/2023] Open
Abstract
The properties of lignocellulosic substrates obtained from different pretreatments have a big impact on downstream saccharification based on both the fungal cellulase system and the cellulosome-based whole-cell biocatalysis system. However the corresponding effect of these two distinct saccharification strategies has not been comparatively analyzed. In this work, three ammonium sulfite (AS)-based pretreatment combinations (i.e., AS + hydrothermal (HT) pretreatment, AS + xylanase (X) pretreatment, and HT + AS pretreatment) were conducted to treat wheat straw. The obtained pretreated substrates with different properties were saccharified using fungal cellulase or an engineered Clostridium thermocellum strain as the whole-cell biocatalyst, and the ability to release sugar was comparatively evaluated. It was found that for the whole-cell saccharification, the total sugar digestibility of AS + HT/X pretreated wheat straw was 10% higher than that of HT + AS pretreated wheat straw. However, for fungal cellulase-based saccharification, the enzymatic hydrolysis efficiency was less susceptible to the sequence of pretreatment combinations. Hence, the whole-cell biocatalysis system was more sensitive to substrate accessibility compared to the free enzymes. In addition, the characterization and analyses showed that AS + HT/X pretreatment could remove more lignin, generating a more accessible surface with a larger external surface and lower surface lignin coverage, compared to the HT + AS pretreatment. Therefore, the AS + HT/X pretreatment was more compatible with the cellulosome-based whole-cell saccharification. The impact of substrate properties on wheat straw sugar release from fungal cellulase and whole cell-based CBS was comparatively investigated.![]()
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Affiliation(s)
- Guang Yu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Shiyue Liu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Xiaoyan Feng
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Yuedong Zhang
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Chao Liu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Bin Li
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Qiu Cui
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Hui Peng
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
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20
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Genetically Modified Microbes for Second-Generation Bioethanol Production. Fungal Biol 2020. [DOI: 10.1007/978-3-030-41870-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Kozaki R, Miyake H. Enzymatic and molecular characterization of an endoglucanase E from Clostridium cellulovorans 743B. J Biosci Bioeng 2019; 128:398-404. [DOI: 10.1016/j.jbiosc.2019.03.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/08/2019] [Accepted: 03/15/2019] [Indexed: 10/27/2022]
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22
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Barruetabeña N, Alonso-Lerma B, Galera-Prat A, Joudeh N, Barandiaran L, Aldazabal L, Arbulu M, Alcalde M, De Sancho D, Gavira JA, Carrion-Vazquez M, Perez-Jimenez R. Resurrection of efficient Precambrian endoglucanases for lignocellulosic biomass hydrolysis. Commun Chem 2019. [DOI: 10.1038/s42004-019-0176-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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23
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Chen L, Wei Y, Shi M, Li Z, Zhang SH. An Archaeal Chitinase With a Secondary Capacity for Catalyzing Cellulose and Its Biotechnological Applications in Shell and Straw Degradation. Front Microbiol 2019; 10:1253. [PMID: 31244795 PMCID: PMC6579819 DOI: 10.3389/fmicb.2019.01253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/20/2019] [Indexed: 12/20/2022] Open
Abstract
Numerous thermostable enzymes have been reported from the hyperthermophilic archaeon Thermococcus kodakarensis KOD1, which made it an attractive resource for gene cloning. This research reported a glycosyl hydrolase (Tk-ChiA) form T. Kodakarensis with dual hydrolytic activity due to the presence of three binding domains with affinity toward chitin and cellulose. The Tk-ChiA gene was cloned and expressed on Pichia pastoris GS115. The molecular weight of the purified Tk-ChiA is about 130.0 kDa. By using chitosan, CMC-Na and other polysaccharides as substrates, we confirmed that Tk-ChiA with dual hydrolysis activity preferably hydrolyzes both chitosan and CMC-Na. Purified Tk-ChiA showed maximal activity for hydrolyzing CMC-Na at temperature 65°C and pH 7.0. It showed thermal stability on incubation for 4 h at temperatures ranging from 70 to 80°C and remained more than 40% of its maximum activity after pre-incubation at 100°C for 4 h. Particularly, Tk-ChiA is capable of degrading shrimp shell and rice straw through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis. The main factors affecting shell and straw degradation were determined to be reaction time and temperature; and both factors were optimized by central composite design (CCD) of response surface methodology (RSM) to enhance the efficiency of degradation. Our findings suggest that Tk-ChiA with dual thermostable hydrolytic activities maybe a promising hydrolase for shell and straw waste treatment, conversion, and utilization.
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Affiliation(s)
- Lina Chen
- College of Plant Sciences, Jilin University, Changchun, China.,College of Food Science and Engineering, Changchun University, Changchun, China
| | - Yi Wei
- College of Plant Sciences, Jilin University, Changchun, China
| | - Mao Shi
- Jilin Provincial Center for Disease Control and Prevention, Changchun, China
| | - Zhengqun Li
- College of Plant Sciences, Jilin University, Changchun, China
| | - Shi-Hong Zhang
- College of Plant Sciences, Jilin University, Changchun, China
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24
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Zhivin-Nissan O, Dassa B, Morag E, Kupervaser M, Levin Y, Bayer EA. Unraveling essential cellulosomal components of the ( Pseudo) Bacteroides cellulosolvens reveals an extensive reservoir of novel catalytic enzymes. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:115. [PMID: 31086567 PMCID: PMC6507058 DOI: 10.1186/s13068-019-1447-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/20/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND (Pseudo)Bacteroides cellulosolvens is a cellulolytic bacterium that produces the most extensive and intricate cellulosomal system known in nature. Recently, the elaborate architecture of the B. cellulosolvens cellulosomal system was revealed from analysis of its genome sequence, and the first evidence regarding the interactions between its structural and enzymatic components were detected in vitro. Yet, the understanding of the cellulolytic potential of the bacterium in carbohydrate deconstruction is inextricably linked to its high-molecular-weight protein complexes, which are secreted from the bacterium. RESULTS The current proteome-wide work reveals patterns of protein expression of the various cellulosomal components, and explores the signature of differential expression upon growth of the bacterium on two major carbon sources-cellobiose and microcrystalline cellulose. Mass spectrometry analysis of the bacterial secretome revealed the expression of 24 scaffoldin structural units and 166 dockerin-bearing components (mainly enzymes), in addition to free enzymatic subunits. The dockerin-bearing components comprise cell-free and cell-bound cellulosomes for more efficient carbohydrate degradation. Various glycoside hydrolase (GH) family members were represented among 102 carbohydrate-degrading enzymes, including the omnipresent, most abundant GH48 exoglucanase. Specific cellulosomal components were found in different molecular-weight fractions associated with cell growth on different carbon sources. Overall, microcrystalline cellulose-derived cellulosomes showed markedly higher expression levels of the structural and enzymatic components, and exhibited the highest degradation activity on five different cellulosic and/or hemicellulosic carbohydrates. The cellulosomal activity of B. cellulosolvens showed high degradation rates that are very promising in biotechnological terms and were compatible with the activity levels exhibited by Clostridium thermocellum purified cellulosomes. CONCLUSIONS The current research demonstrates the involvement of key cellulosomal factors that participate in the mechanism of carbohydrate degradation by B. cellulosolvens. The powerful ability of the bacterium to exhibit different degradation strategies on various carbon sources was revealed. The novel reservoir of cellulolytic components of the cellulosomal degradation machineries may serve as a pool for designing new cellulolytic cocktails for biotechnological purposes.
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Affiliation(s)
- Olga Zhivin-Nissan
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Bioinformatics Unit, Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Ely Morag
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Meital Kupervaser
- Proteomics Unit, Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Yishai Levin
- Proteomics Unit, Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
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Andrei AŞ, Salcher MM, Mehrshad M, Rychtecký P, Znachor P, Ghai R. Niche-directed evolution modulates genome architecture in freshwater Planctomycetes. THE ISME JOURNAL 2019; 13:1056-1071. [PMID: 30610231 PMCID: PMC6461901 DOI: 10.1038/s41396-018-0332-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/22/2018] [Accepted: 11/29/2018] [Indexed: 11/08/2022]
Abstract
Freshwater environments teem with microbes that do not have counterparts in culture collections or genetic data available in genomic repositories. Currently, our apprehension of evolutionary ecology of freshwater bacteria is hampered by the difficulty to establish organism models for the most representative clades. To circumvent the bottlenecks inherent to the cultivation-based techniques, we applied ecogenomics approaches in order to unravel the evolutionary history and the processes that drive genome architecture in hallmark freshwater lineages from the phylum Planctomycetes. The evolutionary history inferences showed that sediment/soil Planctomycetes transitioned to aquatic environments, where they gave rise to new freshwater-specific clades. The most abundant lineage was found to have the most specialised lifestyle (increased regulatory genetic circuits, metabolism tuned for mineralization of proteinaceous sinking aggregates, psychrotrophic behaviour) within the analysed clades and to harbour the smallest freshwater Planctomycetes genomes, highlighting a genomic architecture shaped by niche-directed evolution (through loss of functions and pathways not needed in the newly acquired freshwater niche).
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Affiliation(s)
- Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic.
| | - Michaela M Salcher
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Seestrasse 187, 8802, Kilchberg, Switzerland
| | - Maliheh Mehrshad
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
| | - Pavel Rychtecký
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
| | - Petr Znachor
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic.
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Dou TY, Chen J, Hao YF, Qi X. Effects of Different Carbon Sources on Enzyme Production and Ultrastructure of Cellulosimicrobium cellulans. Curr Microbiol 2019; 76:355-360. [PMID: 30684027 DOI: 10.1007/s00284-019-01633-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/17/2019] [Indexed: 01/18/2023]
Abstract
The secretomes of the strain Cellulosimicrobium cellulans F16 grown on different carbon sources were analyzed by zymography, and the subcellular surface structures were extensively studied by electron microscope. The exo-cellulase and xylanase systems were sparse when cells were grown on soluble oligosaccharides, but were significantly increased when grown on complex and water-insoluble polysaccharides, such as Avicel, corn cob, and birchwood xylan. The cellulosome-like protuberant structures were clearly observed on the cell surfaces of strain F16 grown on cellulose, with diameters of 15-20 nm. Fibrous structures that connected the adjacent cells can be seen under microscope. Moreover, protuberances that adsorbed the cell to cellulose were also observed. As the adhesion of Cellulosimicrobium cellulans cells onto cellulose surfaces occurs via thick bacterial curdlan-type exopolysaccharides (EPS), such surface layer is potentially important in the digestion of insoluble substrates such as cellulose or hemicellulose, and the previously reported xylanosomes are part of such complex glycocalyx layer on the surface of the bacterial cell.
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Affiliation(s)
- Tong-Yi Dou
- School of Life Science and Medicine, Dalian University of Technology, Dagong Road No. 2, LiaoDongWan New District, Panjin, 124221, China.
| | - Jing Chen
- School of Life Science and Medicine, Dalian University of Technology, Dagong Road No. 2, LiaoDongWan New District, Panjin, 124221, China
| | - Yi-Fu Hao
- School of Life Science and Medicine, Dalian University of Technology, Dagong Road No. 2, LiaoDongWan New District, Panjin, 124221, China
| | - Xiaohui Qi
- College of Life Science, Dalian Minzu University, Dalian, 116600, China
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Jeng WY, Liu CI, Lu TJ, Lin HJ, Wang NC, Wang AHJ. Crystal Structures of the C-Terminally Truncated Endoglucanase Cel9Q from Clostridium thermocellum Complexed with Cellodextrins and Tris. Chembiochem 2019; 20:295-307. [PMID: 30609216 DOI: 10.1002/cbic.201800789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Indexed: 11/11/2022]
Abstract
Endoglucanase CtCel9Q is one of the enzyme components of the cellulosome, which is an active cellulase system in the thermophile Clostridium thermocellum. The precursor form of CtCel9Q comprises a signal peptide, a glycoside hydrolase family 9 catalytic domain, a type 3c carbohydrate-binding module (CBM), and a type I dockerin domain. Here, we report the crystal structures of C-terminally truncated CtCel9Q (CtCel9QΔc) complexed with Tris, Tris+cellobiose, cellobiose+cellotriose, cellotriose, and cellotetraose at resolutions of 1.50, 1.70, 2.05, 2.05 and 1.75 Å, respectively. CtCel9QΔc forms a V-shaped homodimer through residues Lys529-Glu542 on the type 3c CBM, which pairs two β-strands (β4 and β5 of the CBM). In addition, a disulfide bond was formed between the two Cys535 residues of the protein monomers in the asymmetric unit. The structures allow the identification of four minus (-) subsites and two plus (+) subsites; this is important for further understanding the structural basis of cellulose binding and hydrolysis. In the oligosaccharide-free and cellobiose-bound CtCel9QΔc structures, a Tris molecule was found to be bound to three catalytic residues of CtCel9Q and occupied subsite -1 of the CtCel9Q active-site cleft. Moreover, the enzyme activity assay in the presence of 100 mm Tris showed that the Tris almost completely suppressed CtCel9Q hydrolase activity.
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Affiliation(s)
- Wen-Yih Jeng
- University Center for Bioscience and Biotechnology, National Cheng Kung University, 1 University Road, Tainan, 701, Taiwan.,Department of Biochemistry and Molecular Biology, National Cheng Kung University, 1 University Road, Tainan, 701, Taiwan
| | - Chia-I Liu
- School of Medical Laboratory Science and Biotechnology, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
| | - Te-Jung Lu
- Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, 89 Wenhua 1st Street, Tainan, 717, Taiwan
| | - Hong-Jie Lin
- University Center for Bioscience and Biotechnology, National Cheng Kung University, 1 University Road, Tainan, 701, Taiwan
| | - Nai-Chen Wang
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Sec. 2, Taipei, 115, Taiwan
| | - Andrew H-J Wang
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Sec 2, Taipei, 115, Taiwan
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Ren Z, You W, Wu S, Poetsch A, Xu C. Secretomic analyses of Ruminiclostridium papyrosolvens reveal its enzymatic basis for lignocellulose degradation. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:183. [PMID: 31338125 PMCID: PMC6628489 DOI: 10.1186/s13068-019-1522-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 07/05/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Efficient biotechnological conversion of lignocellulosic biomass to valuable products, such as transportation biofuels, is ecologically attractive, yet requires substantially improved mechanistic understanding and optimization to become economically feasible. Cellulolytic clostridia, such as Ruminiclostridium papyrosolvens (previously Clostridium papyrosolvens), produce a wide variety of carbohydrate-active enzymes (CAZymes) including extracellular multienzyme complexes-cellulosomes with different specificities for enhanced cellulosic biomass degradation. Identification of the secretory components, especially CAZymes, during bacterial growth on lignocellulose and their influence on bacterial catalytic capabilities provide insight into construction of potent cellulase systems of cell factories tuned or optimized for the targeted substrate by matching the type and abundance of enzymes and corresponding transporters. RESULTS In this study, we firstly predicted a total of 174 putative CAZymes from the genome of R. papyrosolvens, including 74 cellulosomal components. To explore profile of secreted proteins involved in lignocellulose degradation, we compared the secretomes of R. papyrosolvens grown on different substrates using label-free quantitative proteomics. CAZymes, extracellular solute-binding proteins (SBPs) of transport systems and proteins involved in spore formation were enriched in the secretome of corn stover for lignocellulose degradation. Furthermore, compared with free CAZymes, complex CAZymes (cellulosomal components) had larger fluctuations in variety and abundance of enzymes among four carbon sources. In particular, cellulosomal proteins encoded by the cip-cel operon and the xyl-doc gene cluster had the highest abundance with corn stover as substrate. Analysis of differential expression of CAZymes revealed a substrate-dependent secretion pattern of CAZymes, which was consistent with their catalytic activity from each secretome determined on different cellulosic substrates. The results suggest that the expression of CAZymes is regulated by the type of substrate in the growth medium. CONCLUSIONS In the present study, our results demonstrated the complexity of the lignocellulose degradation systems of R. papyrosolvens and showed the potency of its biomass degradation activity. Differential proteomic analyses and activity assays of CAZymes secreted by R. papyrosolvens suggested a distinct environment-sensing strategy for cellulose utilization in which R. papyrosolvens modulated the composition of the CAZymes, especially cellulosome, according to the degradation state of its natural substrate.
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Affiliation(s)
- Zhenxing Ren
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi China
- Institute of Applied Chemistry, Shanxi University, Taiyuan, 030006 Shanxi China
| | - Wuxin You
- Department of Plant Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Shasha Wu
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi China
| | - Ansgar Poetsch
- Department of Plant Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
- School of Biomedical and Healthcare Sciences, University of Plymouth, Plymouth, PL48AA UK
| | - Chenggang Xu
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi China
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Abstract
Cooperative enzyme catalysis in nature has long inspired the application of engineered multi-enzyme assemblies for industrial biocatalysis. Despite considerable interest, efforts to harness the activity of cell-surface displayed multi-enzyme assemblies have been based on trial and error rather than rational design due to a lack of quantitative tools. In this study, we developed a quantitative approach to whole-cell biocatalyst characterization enabling a comprehensive study of how yeast-surface displayed multi-enzyme assemblies form. Here we show that the multi-enzyme assembly efficiency is limited by molecular crowding on the yeast cell surface, and that maximizing enzyme density is the most important parameter for enhancing cellulose hydrolytic performance. Interestingly, we also observed that proximity effects are only synergistic when the average inter-enzyme distance is > ~130 nm. The findings and the quantitative approach developed in this work should help to advance the field of biocatalyst engineering from trial and error to rational design.
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Li R, Feng Y, Liu S, Qi K, Cui Q, Liu YJ. Inducing effects of cellulosic hydrolysate components of lignocellulose on cellulosome synthesis in Clostridium thermocellum. Microb Biotechnol 2018; 11:905-916. [PMID: 29943510 PMCID: PMC6116742 DOI: 10.1111/1751-7915.13293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/25/2018] [Accepted: 06/04/2018] [Indexed: 02/06/2023] Open
Abstract
Cellulosome is a highly efficient supramolecular machine for lignocellulose degradation, and its substrate‐coupled regulation requires soluble transmembrane signals. However, the inducers for cellulosome synthesis and the inducing effect have not been clarified quantitatively. Values of cellulosome production capacity (CPC) and estimated specific activity (eSA) were calculated based on the primary scaffoldin ScaA to define the stimulating effects on the cellulosome synthesis in terms of quantity and quality respectively. The estimated cellulosome production of Clostridium thermocellum on glucose was at a low housekeeping level. Both Avicel and cellobiose increased CPCs of the cells instead of the eSAs of the cellulosome. The CPC of Avicel‐grown cells was over 20‐fold of that of glucose‐grown cells, while both Avicel‐ and glucose‐derived cellulosomes showed similar eSA. The CPC of cellobiose‐grown cells was also over three times higher than glucose‐grown cells, but the eSA of cellobiose‐derived cellulosome was 16% lower than that of the glucose‐derived cellulosome. Our results indicated that cello‐oligosaccharides played the key roles in inducing the synthesis of the cellulosome, but non‐cellulosic polysaccharides showed no inducing effects.
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Affiliation(s)
- Renmin Li
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yingang Feng
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Shiyue Liu
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Kuan Qi
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qiu Cui
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Ya-Jun Liu
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
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31
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Chang JJ, Anandharaj M, Ho CY, Tsuge K, Tsai TY, Ke HM, Lin YJ, Ha Tran MD, Li WH, Huang CC. Biomimetic strategy for constructing Clostridium thermocellum cellulosomal operons in Bacillus subtilis. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:157. [PMID: 29930703 PMCID: PMC5991470 DOI: 10.1186/s13068-018-1151-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Enzymatic conversion of lignocellulosic biomass into soluble sugars is a major bottleneck in the plant biomass utilization. Several anaerobic organisms cope these issues via multiple-enzyme complex system so called 'cellulosome'. Hence, we proposed a "biomimic operon" concept for making an artificial cellulosome which can be used as a promising tool for the expression of cellulosomal enzymes in Bacillus subtilis. RESULTS According to the proteomic analysis of Clostridium thermocellum ATCC27405 induced by Avicel or cellobiose, we selected eight highly expressed cellulosomal genes including a scaffoldin protein gene (cipA), a cell-surface anchor gene (sdbA), two exoglucanase genes (celK and celS), two endoglucanase genes (celA and celR), and two xylanase genes (xynC and xynZ). Arranging these eight genes in two different orders, we constructed two different polycistronic operons using the ordered gene assembly in Bacillus method. This is the first study to express the whole CipA along with cellulolytic enzymes in B. subtilis. Each operon was successfully expressed in B. subtilis RM125, and the protein complex assembly, cellulose-binding ability, thermostability, and cellulolytic activity were demonstrated. The operon with a higher xylanase activity showed greater saccharification on complex cellulosic substrates such as Napier grass than the other operon. CONCLUSIONS In this study, a strategy for constructing an efficient cellulosome system was developed and two different artificial cellulosomal operons were constructed. Both operons could efficiently express the cellulosomal enzymes and exhibited cellulose saccharification. This strategy can be applied to different industries with cellulose-containing materials, such as papermaking, biofuel, agricultural compost, mushroom cultivation, and waste processing industries.
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Affiliation(s)
- Jui-Jen Chang
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, 402 Taiwan
| | - Marimuthu Anandharaj
- Biodiversity Research Center, Academia Sinica, Taipei, 11529 Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei, 11529 Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227 Taiwan
| | - Cheng-Yu Ho
- Department of Life Sciences, National Chung Hsing University, Taichung, 40227 Taiwan
| | - Kenji Tsuge
- Institute for Advanced Biosciences, Keio University, 403-1 Nipponkoku, Daihoji, Tsuruoka, Yamagata 997-0017 Japan
| | - Tsung-Yu Tsai
- Biodiversity Research Center, Academia Sinica, Taipei, 11529 Taiwan
| | - Huei-Mien Ke
- Biodiversity Research Center, Academia Sinica, Taipei, 11529 Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227 Taiwan
| | - Yu-Ju Lin
- Biodiversity Research Center, Academia Sinica, Taipei, 11529 Taiwan
| | - Minh Dung Ha Tran
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei, 11529 Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227 Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung, 40227 Taiwan
| | - Wen-Hsiung Li
- Biodiversity Research Center, Academia Sinica, Taipei, 11529 Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei, 11529 Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227 Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 40227 Taiwan
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637 USA
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, 40227 Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung, 40227 Taiwan
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Zou X, Ren Z, Wang N, Cheng Y, Jiang Y, Wang Y, Xu C. Function analysis of 5'-UTR of the cellulosomal xyl- doc cluster in Clostridium papyrosolvens. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:43. [PMID: 29467821 PMCID: PMC5815224 DOI: 10.1186/s13068-018-1040-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 02/02/2018] [Indexed: 05/04/2023]
Abstract
BACKGROUND Anaerobic, mesophilic, and cellulolytic Clostridium papyrosolvens produces an efficient cellulolytic extracellular complex named cellulosome that hydrolyzes plant cell wall polysaccharides into simple sugars. Its genome harbors two long cellulosomal clusters: cip-cel operon encoding major cellulosome components (including scaffolding) and xyl-doc gene cluster encoding hemicellulases. Compared with works on cip-cel operon, there are much fewer studies on xyl-doc mainly due to its rare location in cellulolytic clostridia. Sequence analysis of xyl-doc revealed that it harbors a 5' untranslated region (5'-UTR) which potentially plays a role in the regulation of downstream gene expression. Here, we analyzed the function of 5'-UTR of xyl-doc cluster in C. papyrosolvens in vivo via transformation technology developed in this study. RESULTS In this study, we firstly developed an electrotransformation method for C. papyrosolvens DSM 2782 before the analysis of 5'-UTR of xyl-doc cluster. In the optimized condition, a field with an intensity of 7.5-9.0 kV/cm was applied to a cuvette (0.2 cm gap) containing a mixture of plasmid and late cell suspended in exponential phase to form a 5 ms pulse in a sucrose-containing buffer. Afterwards, the putative promoter and the 5'-UTR of xyl-doc cluster were determined by sequence alignment. It is indicated that xyl-doc possesses a long conservative 5'-UTR with a complex secondary structure encompassing at least two perfect stem-loops which are potential candidates for controlling the transcriptional termination. In the last step, we employed an oxygen-independent flavin-based fluorescent protein (FbFP) as a quantitative reporter to analyze promoter activity and 5'-UTR function in vivo. It revealed that 5'-UTR significantly blocked transcription of downstream genes, but corn stover can relieve its suppression. CONCLUSIONS In the present study, our results demonstrated that 5'-UTR of the cellulosomal xyl-doc cluster blocks the transcriptional activity of promoter. However, some substrates, such as corn stover, can relieve the effect of depression of 5'-UTR. Thus, it is speculated that 5'-UTR of xyl-doc was a putative riboswitch to regulate the expression of downstream cellulosomal genes, which is helpful to understand the complex regulation of cellulosome.
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Affiliation(s)
- Xia Zou
- Research Center for Harmful Algae and Marine Biology, College of Life Science and Technology, Jinan University, Guangzhou, 510632 Guangdong Province China
| | - Zhenxing Ren
- Institute of Applied Chemistry, Shanxi University, Taiyuan, 030006 Shanxi Province China
| | - Na Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi Province China
| | - Yin Cheng
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi Province China
| | - Yuanyuan Jiang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi Province China
| | - Yan Wang
- Research Center for Harmful Algae and Marine Biology, College of Life Science and Technology, Jinan University, Guangzhou, 510632 Guangdong Province China
| | - Chenggang Xu
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006 Shanxi Province China
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and BioProcess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong Province China
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Różycki B, Cazade PA, O'Mahony S, Thompson D, Cieplak M. The length but not the sequence of peptide linker modules exerts the primary influence on the conformations of protein domains in cellulosome multi-enzyme complexes. Phys Chem Chem Phys 2018; 19:21414-21425. [PMID: 28758665 DOI: 10.1039/c7cp04114d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cellulosomes are large multi-protein catalysts produced by various anaerobic microorganisms to efficiently degrade plant cell-wall polysaccharides down into simple sugars. X-ray and physicochemical structural characterisations show that cellulosomes are composed of numerous protein domains that are connected by unstructured polypeptide segments, yet the properties and possible roles of these 'linker' peptides are largely unknown. We have performed coarse-grained and all-atom molecular dynamics computer simulations of a number of cellulosomal linkers of different lengths and compositions. Our data demonstrates that the effective stiffness of the linker peptides, as quantified by the equilibrium fluctuations in the end-to-end distances, depends primarily on the length of the linker and less so on the specific amino acid sequence. The presence of excluded volume - provided by the domains that are connected - dampens the motion of the linker residues and reduces the effective stiffness of the linkers. Simultaneously, the presence of the linkers alters the conformations of the protein domains that are connected. We demonstrate that short, stiff linkers induce significant rearrangements in the folded domains of the mini-cellulosome composed of endoglucanase Cel8A in complex with scaffoldin ScafT (Cel8A-ScafT) of Clostridium thermocellum as well as in a two-cohesin system derived from the scaffoldin ScaB of Acetivibrio cellulolyticus. We give experimentally testable predictions on structural changes in protein domains that depend on the length of linkers.
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Affiliation(s)
- Bartosz Różycki
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
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Brunecky R, Chung D, Sarai NS, Hengge N, Russell JF, Young J, Mittal A, Pason P, Vander Wall T, Michener W, Shollenberger T, Westpheling J, Himmel ME, Bomble YJ. High activity CAZyme cassette for improving biomass degradation in thermophiles. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:22. [PMID: 29434665 PMCID: PMC5793385 DOI: 10.1186/s13068-018-1014-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/09/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND Thermophilic microorganisms and their enzymes offer several advantages for industrial application over their mesophilic counterparts. For example, a hyperthermophilic anaerobe, Caldicellulosiruptor bescii, was recently isolated from hot springs in Kamchatka, Siberia, and shown to have very high cellulolytic activity. Additionally, it is one of a few microorganisms being considered as viable candidates for consolidated bioprocessing applications. Moreover, C. bescii is capable of deconstructing plant biomass without enzymatic or chemical pretreatment. This ability is accomplished by the production and secretion of free, multi-modular and multi-functional enzymes, one of which, CbCel9A/Cel48A also known as CelA, is able to outperform enzymes found in commercial enzyme preparations. Furthermore, the complete C. bescii exoproteome is extremely thermostable and highly active at elevated temperatures, unlike commercial fungal cellulases. Therefore, understanding the functional diversity of enzymes in the C. bescii exoproteome and how inter-molecular synergy between them confers C. bescii with its high cellulolytic activity is an important endeavor to enable the production of more efficient biomass degrading enzyme formulations and in turn, better cellulolytic industrial microorganisms. RESULTS To advance the understanding of the C. bescii exoproteome we have expressed, purified, and tested four of the primary enzymes found in the exoproteome and we have found that the combination of three or four of the most highly expressed enzymes exhibit synergistic activity. We also demonstrated that discrete combinations of these enzymes mimic and even improve upon the activity of the whole C. bescii exoproteome, even though some of the enzymes lack significant activity on their own. CONCLUSIONS We have demonstrated that it is possible to replicate the cellulolytic activity of the native C. bescii exoproteome utilizing a minimal gene set, and that these minimal gene sets are more active than the whole exoproteome. In the future, this may lead to more simplified and efficient cellulolytic enzyme preparations or yield improvements when these enzymes are expressed in microorganisms engineered for consolidated bioprocessing.
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Affiliation(s)
- Roman Brunecky
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Daehwan Chung
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Nicholas S. Sarai
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Neal Hengge
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | | | - Jenna Young
- Department of Genetics, University of Georgia, Athens, GA 30602 USA
| | - Ashutosh Mittal
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Patthra Pason
- Development and Training Institute, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
| | - Todd Vander Wall
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - William Michener
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Todd Shollenberger
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | | | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
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Bomble YJ, Lin CY, Amore A, Wei H, Holwerda EK, Ciesielski PN, Donohoe BS, Decker SR, Lynd LR, Himmel ME. Lignocellulose deconstruction in the biosphere. Curr Opin Chem Biol 2017; 41:61-70. [DOI: 10.1016/j.cbpa.2017.10.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 12/18/2022]
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Zhivin O, Dassa B, Moraïs S, Utturkar SM, Brown SD, Henrissat B, Lamed R, Bayer EA. Unique organization and unprecedented diversity of the Bacteroides (Pseudobacteroides) cellulosolvens cellulosome system. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:211. [PMID: 28912832 PMCID: PMC5590126 DOI: 10.1186/s13068-017-0898-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/29/2017] [Indexed: 05/23/2023]
Abstract
BACKGROUND (Pseudo) Bacteroides cellulosolvens is an anaerobic, mesophilic, cellulolytic, cellulosome-producing clostridial bacterium capable of utilizing cellulose and cellobiose as carbon sources. Recently, we sequenced the B. cellulosolvens genome, and subsequent comprehensive bioinformatic analysis, herein reported, revealed an unprecedented number of cellulosome-related components, including 78 cohesin modules scattered among 31 scaffoldins and more than 200 dockerin-bearing ORFs. In terms of numbers, the B. cellulosolvens cellulosome system represents the most intricate, compositionally diverse cellulosome system yet known in nature. RESULTS The organization of the B. cellulosolvens cellulosome is unique compared to previously described cellulosome systems. In contrast to all other known cellulosomes, the cohesin types are reversed for all scaffoldins i.e., the type II cohesins are located on the enzyme-integrating primary scaffoldin, whereas the type I cohesins are located on the anchoring scaffoldins. Many of the type II dockerin-bearing ORFs include X60 modules, which are known to stabilize type II cohesin-dockerin interactions. In the present work, we focused on revealing the architectural arrangement of cellulosome structure in this bacterium by examining numerous interactions between the various cohesin and dockerin modules. In total, we cloned and expressed 43 representative cohesins and 27 dockerins. The results revealed various possible architectures of cell-anchored and cell-free cellulosomes, which serve to assemble distinctive cellulosome types via three distinct cohesin-dockerin specificities: type I, type II, and a novel-type designated R (distinct from type III interactions, predominant in ruminococcal cellulosomes). CONCLUSIONS The results of this study provide novel insight into the architecture and function of the most intricate and extensive cellulosomal system known today, thereby extending significantly our overall knowledge base of cellulosome systems and their components. The robust cellulosome system of B. cellulosolvens, with its unique binding specificities and reversal of cohesin-dockerin types, has served to amend our view of the cellulosome paradigm. Revealing new cellulosomal interactions and arrangements is critical for designing high-efficiency artificial cellulosomes for conversion of plant-derived cellulosic biomass towards improved production of biofuels.
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Affiliation(s)
- Olga Zhivin
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Sarah Moraïs
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Sagar M. Utturkar
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919 USA
- BioEnergy Science Center, Oak Ridge, TN USA
| | - Steven D. Brown
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919 USA
- BioEnergy Science Center, Oak Ridge, TN USA
- Biosciences Division, Energy and Environment Directorate, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille University and CNRS, Marseille, France
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Edward A. Bayer
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
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The unusual cellulose utilization system of the aerobic soil bacterium Cytophaga hutchinsonii. Appl Microbiol Biotechnol 2017; 101:7113-7127. [PMID: 28849247 DOI: 10.1007/s00253-017-8467-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/05/2017] [Indexed: 10/19/2022]
Abstract
Cellulolytic microorganisms play important roles in global carbon cycling and have evolved diverse strategies to digest cellulose. Some are 'generous,' releasing soluble sugars from cellulose extracellularly to feed both themselves and their neighbors. The gliding soil bacterium Cytophaga hutchinsonii exhibits a more 'selfish' strategy. It digests crystalline cellulose using cell-associated cellulases and releases little soluble sugar outside of the cell. The mechanism of C. hutchinsonii cellulose utilization is still poorly understood. In this review, we discuss novel aspects of the C. hutchinsonii cellulolytic system. Recently developed genetic manipulation tools allowed the identification of proteins involved in C. hutchinsonii cellulose utilization. These include periplasmic and cell-surface endoglucanases and novel cellulose-binding proteins. The recently discovered type IX secretion system is needed for cellulose utilization and appears to deliver some of the cellulolytic enzymes and other proteins to the cell surface. The requirement for periplasmic endoglucanases for cellulose utilization is unusual and suggests that cello-oligomers must be imported across the outer membrane before being further digested. Cellobiohydrolases or other predicted processive cellulases that play important roles in many other cellulolytic bacteria appear to be absent in C. hutchinsonii. Cells of C. hutchinsonii attach to and glide along cellulose fibers, which may allow them to find sites most amenable to attack. A model of C. hutchinsonii cellulose utilization summarizing recent progress is proposed.
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Szczupak A, Aizik D, Moraïs S, Vazana Y, Barak Y, Bayer EA, Alfonta L. The Electrosome: A Surface-Displayed Enzymatic Cascade in a Biofuel Cell's Anode and a High-Density Surface-Displayed Biocathodic Enzyme. NANOMATERIALS (BASEL, SWITZERLAND) 2017; 7:E153. [PMID: 28644390 PMCID: PMC5535219 DOI: 10.3390/nano7070153] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/12/2017] [Accepted: 06/20/2017] [Indexed: 11/29/2022]
Abstract
The limitation of surface-display systems in biofuel cells to a single redox enzyme is a major drawback of hybrid biofuel cells, resulting in a low copy-number of enzymes per yeast cell and a limitation in displaying enzymatic cascades. Here we present the electrosome, a novel surface-display system based on the specific interaction between the cellulosomal scaffoldin protein and a cascade of redox enzymes that allows multiple electron-release by fuel oxidation. The electrosome is composed of two compartments: (i) a hybrid anode, which consists of dockerin-containing enzymes attached specifically to cohesin sites in the scaffoldin to assemble an ethanol oxidation cascade, and (ii) a hybrid cathode, which consists of a dockerin-containing oxygen-reducing enzyme attached in multiple copies to the cohesin-bearing scaffoldin. Each of the two compartments was designed, displayed, and tested separately. The new hybrid cell compartments displayed enhanced performance over traditional biofuel cells; in the anode, the cascade of ethanol oxidation demonstrated higher performance than a cell with just a single enzyme. In the cathode, a higher copy number per yeast cell of the oxygen-reducing enzyme copper oxidase has reduced the effect of competitive inhibition resulting from yeast oxygen consumption. This work paves the way for the assembly of more complex cascades using different enzymes and larger scaffoldins to further improve the performance of hybrid cells.
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Affiliation(s)
- Alon Szczupak
- Department of Life Sciences and the Ilse Katz Institute for Nanoscale Science and Technology, P.O. Box 653, 8410501 Beer-Sheva, Israel.
| | - Dror Aizik
- Department of Life Sciences and the Ilse Katz Institute for Nanoscale Science and Technology, P.O. Box 653, 8410501 Beer-Sheva, Israel.
| | - Sarah Moraïs
- Department of Biomolecular Sciences, Weizmann Institute of Science, 234 Herzl St., P.O. Box 26, 7610001 Rehovot, Israel.
| | - Yael Vazana
- Department of Biomolecular Sciences, Weizmann Institute of Science, 234 Herzl St., P.O. Box 26, 7610001 Rehovot, Israel.
| | - Yoav Barak
- Department of Chemical Research Support, Weizmann Institute of Science, 234 Herzl St., P.O. Box 26, 7610001 Rehovot, Israel.
| | - Edward A Bayer
- Department of Biomolecular Sciences, Weizmann Institute of Science, 234 Herzl St., P.O. Box 26, 7610001 Rehovot, Israel.
| | - Lital Alfonta
- Department of Life Sciences and the Ilse Katz Institute for Nanoscale Science and Technology, P.O. Box 653, 8410501 Beer-Sheva, Israel.
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Behera B, Sethi B, Mishra R, Dutta S, Thatoi H. Microbial cellulases - Diversity & biotechnology with reference to mangrove environment: A review. J Genet Eng Biotechnol 2017; 15:197-210. [PMID: 30647656 PMCID: PMC6296582 DOI: 10.1016/j.jgeb.2016.12.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/01/2016] [Indexed: 11/21/2022]
Abstract
Cellulose is an abundant natural biopolymer on earth, found as a major constituent of plant cell wall in lignocellulosic form. Unlike other compounds cellulose is not easily soluble in water hence enzymatic conversion of cellulose has become a key technology for biodegradation of lignocellulosic materials. Microorganisms such as aerobic bacteria, fungi, yeast and actinomycetes produce cellulase that degrade cellulose by hydrolysing the β-1, 4-glycosidic linkages of cellulose. In contrast to aerobic bacteria, anaerobic bacteria lack the ability to effectively penetrate into the cellulosic material which leads to the development of complexed cellulase systems called cellulosome. Among the different environments, the sediments of mangrove forests are suitable for exploring cellulose degrading microorganisms because of continuous input of cellulosic carbon in the form of litter which then acts as a substrate for decomposition by microbe. Understanding the importance of cellulase, the present article overviews the diversity of cellulolytic microbes from different mangrove environments around the world. The molecular mechanism related to cellulase gene regulation, expression and various biotechnological application of cellulase is also discussed.
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Affiliation(s)
- B.C. Behera
- Department of Biotechnology, North Orissa University, Baripada 757003, Odisha, India
| | - B.K. Sethi
- Department of Biotechnology, MITS School of Biotechnology, Bhubaneswar 751024, India
| | - R.R. Mishra
- Department of Biotechnology, MITS School of Biotechnology, Bhubaneswar 751024, India
| | - S.K. Dutta
- Department of Zoology, North Orissa University, Baripada 757003, Odisha, India
| | - H.N. Thatoi
- Department of Biotechnology, North Orissa University, Baripada 757003, Odisha, India
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Bai X, Wang X, Wang S, Ji X, Guan Z, Zhang W, Lu X. Functional Studies of β-Glucosidases of Cytophaga hutchinsonii and Their Effects on Cellulose Degradation. Front Microbiol 2017; 8:140. [PMID: 28210251 PMCID: PMC5288383 DOI: 10.3389/fmicb.2017.00140] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/19/2017] [Indexed: 11/17/2022] Open
Abstract
Cytophaga hutchinsonii can rapidly digest crystalline cellulose without free cellulases or cellulosomes. Its cell-contact cellulose degradation mechanism is unknown. In this study, the four β-glucosidase (bgl) genes in C. hutchinsonii were singly and multiply deleted, and the functions of these β-glucosidases in cellobiose and cellulose degradation were investigated. We found that the constitutively expressed BglB played a key role in cellobiose utilization, while BglA which was induced by cellobiose could partially make up for the deletion of bglB. The double deletion mutant ΔbglA/bglB lost the ability to digest cellobiose and could not thrive in cellulose medium, indicating that β-glucosidases were important for cellulose degradation. When cultured in cellulose medium, a small amount of glucose accumulated in the medium in the initial stage of growth for the wild type, while almost no glucose accumulated for ΔbglA/bglB. When supplemented with a small amount of glucose, ΔbglA/bglB started to degrade cellulose and grew in cellulose medium. We inferred that glucose might be essential for initiating cellulose degradation, and with additional glucose, C. hutchinsonii could partially utilize cellulose without β-glucosidases. We also found that there were both cellulose binding cells and free cells when cultured in cellulose. Since direct contact between C. hutchinsonii cells and cellulose is necessary for cellulose degradation, we deduced that the free cells which were convenient to explore new territory in the environment might be fed by the adherent cells which could produce cello-oligosaccharide and glucose into the environment. This study enriched our knowledge of the cellulolytic pathway of C. hutchinsonii.
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Affiliation(s)
- Xinfeng Bai
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Xifeng Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Sen Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Xiaofei Ji
- Department of Pathogenic Biology, Binzhou Medical University Yantai, China
| | - Zhiwei Guan
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Weican Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Xuemei Lu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
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41
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42
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Optimization of Cellulase and Xylanase Production by Micrococcus Species under Submerged Fermentation. SUSTAINABILITY 2016. [DOI: 10.3390/su8111168] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Takeuchi Y, Khawdas W, Aso Y, Ohara H. Microbial fuel cells using Cellulomonas spp. with cellulose as fuel. J Biosci Bioeng 2016; 123:358-363. [PMID: 27818074 DOI: 10.1016/j.jbiosc.2016.10.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/13/2016] [Accepted: 10/17/2016] [Indexed: 10/20/2022]
Abstract
Cellulomonas fimi, Cellulomonas biazotea, and Cellulomonas flavigena are cellulose-degrading microorganisms chosen to compare the degradation of cellulose. C. fimi degraded 2.5 g/L of cellulose within 4 days, which was the highest quantity among the three microorganisms. The electric current generation by the microbial fuel cell (MFC) using the cellulose-containing medium with C. fimi was measured over 7 days. The medium in the MFC was sampled every 24 h to quantify the degradation of cellulose, and the results showed that the electric current increased with the degradation of cellulose. The maximum electric power generated by the MFC was 38.7 mW/m2, and this numeric value was 63% of the electric power generated by an MFC with Shewanella oneidensis MR-1, a well-known current-generating microorganism. Our results showed that C. fimi was an excellent candidate to produce the electric current from cellulose via MFCs.
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Affiliation(s)
- Yuya Takeuchi
- Department of Biobased Materials Science, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Wichean Khawdas
- Department of Biobased Materials Science, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Yuji Aso
- Department of Biobased Materials Science, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Hitomi Ohara
- Department of Biobased Materials Science, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
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Characterization of a Cellulomonas fimi exoglucanase/xylanase-endoglucanase gene fusion which improves microbial degradation of cellulosic biomass. Enzyme Microb Technol 2016; 93-94:113-121. [DOI: 10.1016/j.enzmictec.2016.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 11/17/2022]
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Bensoussan L, Moraïs S, Dassa B, Friedman N, Henrissat B, Lombard V, Bayer EA, Mizrahi I. Broad phylogeny and functionality of cellulosomal components in the bovine rumen microbiome. Environ Microbiol 2016; 19:185-197. [PMID: 27712009 PMCID: PMC6487960 DOI: 10.1111/1462-2920.13561] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/29/2016] [Indexed: 11/30/2022]
Abstract
The cellulosome is an extracellular multi‐enzyme complex that is considered one of the most efficient plant cell wall‐degrading strategies devised by nature. Its unique modular architecture, achieved by high affinity and specific interaction between protein modules (cohesins and dockerins) enables formation of various enzyme combinations. Extensive research has been dedicated to the mechanistic nature of the cellulosome complex. Nevertheless, little is known regarding its distribution and abundance among microbes in natural plant fibre‐rich environments. Here, we explored these questions in bovine rumen microbial communities, specialized in efficient degradation of lignocellulosic plant material. We bioinformatically screened for cellulosomal modules in this complex environment using a previously published ultra‐deep fibre‐adherent rumen metagenome. Intriguingly, a large portion of the functions of the dockerin‐containing proteins were related to alternative biological processes, and not necessarily to the classic fibre degradation function. Our analysis was experimentally validated by characterizing specific interactions between selected cohesins and dockerins and revealed that cellulosome is a more generalized strategy used by diverse bacteria, some of which were not previously associated with cellulosome production. Remarkably, our results provide additional proof of similarity among rumen microbial communities worldwide. This study suggests a broader and widespread role for the cellulosomal machinery in nature.
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Affiliation(s)
- Lizi Bensoussan
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Sarah Moraïs
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Nir Friedman
- The Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, Aix-Marseille University, CNRS UMR7257, Marseille, France
| | - Vincent Lombard
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, Aix-Marseille University, CNRS UMR7257, Marseille, France
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Itzhak Mizrahi
- The Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Moraïs S, Stern J, Kahn A, Galanopoulou AP, Yoav S, Shamshoum M, Smith MA, Hatzinikolaou DG, Arnold FH, Bayer EA. Enhancement of cellulosome-mediated deconstruction of cellulose by improving enzyme thermostability. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:164. [PMID: 27493686 PMCID: PMC4973527 DOI: 10.1186/s13068-016-0577-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 07/27/2016] [Indexed: 05/25/2023]
Abstract
BACKGROUND The concerted action of three complementary cellulases from Clostridium thermocellum, engineered to be stable at elevated temperatures, was examined on a cellulosic substrate and compared to that of the wild-type enzymes. Exoglucanase Cel48S and endoglucanase Cel8A, both key elements of the natural cellulosome from this bacterium, were engineered previously for increased thermostability, either by SCHEMA, a structure-guided, site-directed protein recombination method, or by consensus-guided mutagenesis combined with random mutagenesis using error-prone PCR, respectively. A thermostable β-glucosidase BglA mutant was also selected from a library generated by error-prone PCR that will assist the two cellulases in their methodic deconstruction of crystalline cellulose. The effects of a thermostable scaffoldin versus those of a largely mesophilic scaffoldin were also examined. By improving the stability of the enzyme subunits and the structural component, we aimed to improve cellulosome-mediated deconstruction of cellulosic substrates. RESULTS The results demonstrate that the combination of thermostable enzymes as free enzymes and a thermostable scaffoldin was more active on the cellulosic substrate than the wild-type enzymes. Significantly, "thermostable" designer cellulosomes exhibited a 1.7-fold enhancement in cellulose degradation compared to the action of conventional designer cellulosomes that contain the respective wild-type enzymes. For designer cellulosome formats, the use of the thermostabilized scaffoldin proved critical for enhanced enzymatic performance under conditions of high temperatures. CONCLUSIONS Simple improvement in the activity of a given enzyme does not guarantee its suitability for use in an enzyme cocktail or as a designer cellulosome component. The true merit of improvement resides in its ultimate contribution to synergistic action, which can only be determined experimentally. The relevance of the mutated thermostable enzymes employed in this study as components in multienzyme systems has thus been confirmed using designer cellulosome technology. Enzyme integration via a thermostable scaffoldin is critical to the ultimate stability of the complex at higher temperatures. Engineering of thermostable cellulases and additional lignocellulosic enzymes may prove a determinant parameter for development of state-of-the-art designer cellulosomes for their employment in the conversion of cellulosic biomass to soluble sugars.Graphical abstractConversion of conventional designer cellulosomes into thermophilic designer cellulosomes.
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Affiliation(s)
- Sarah Moraïs
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Johanna Stern
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Amaranta Kahn
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Anastasia P. Galanopoulou
- Microbiology Group, Faculty of Biology, National and Kapodistrian University of Athens, Zografou Campus, 15784 Athens, Greece
| | - Shahar Yoav
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
- Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100 Rehovot, Israel
| | - Melina Shamshoum
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Matthew A. Smith
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Dimitris G. Hatzinikolaou
- Microbiology Group, Faculty of Biology, National and Kapodistrian University of Athens, Zografou Campus, 15784 Athens, Greece
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
- Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel
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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: 35] [Impact Index Per Article: 4.4] [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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Cunha ES, Hatem CL, Barrick D. Synergistic enhancement of cellulase pairs linked by consensus ankyrin repeats: Determination of the roles of spacing, orientation, and enzyme identity. Proteins 2016; 84:1043-54. [PMID: 27071357 DOI: 10.1002/prot.25047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 03/09/2016] [Accepted: 03/25/2016] [Indexed: 12/22/2022]
Abstract
Biomass deconstruction to small simple sugars is a potential approach to biofuels production; however, the highly recalcitrant nature of biomass limits the economic viability of this approach. Thus, research on efficient biomass degradation is necessary to achieve large-scale production of biofuels. Enhancement of cellulolytic activity by increasing synergism between cellulase enzymes holds promise in achieving high-yield biofuels production. Here we have inserted cellulase pairs from extremophiles into hyperstable α-helical consensus ankyrin repeat domain scaffolds. Such chimeric constructs allowed us to optimize arrays of enzyme pairs against a variety of cellulolytic substrates. We found that endocellulolytic domains CelA (CA) and Cel12A (C12A) act synergistically in the context of ankyrin repeats, with both three and four repeat spacing. The extent of synergy differs for different substrates. Also, having C12A N-terminal to CA provides greater synergy than the reverse construct, especially against filter paper. In contrast, we do not see synergy for these enzymes in tandem with CelK (CK) catalytic domain, a larger exocellulase, demonstrating the importance of enzyme identity in synergistic enhancement. Furthermore, we found endocellulases CelD and CA with three repeat spacing to act synergistically against filter paper. Importantly, connecting CA and C12A with a disordered linker of similar contour length shows no synergistic enhancement, indicating that synergism results from connecting these domains with folded ankyrin repeats. These results show that ankyrin arrays can be used to vary spacing and orientation between enzymes, helping to design and optimize artificial cellulosomes, providing a novel architecture for synergistic enhancement of enzymatic cellulose degradation. Proteins 2016; 84:1043-1054. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Eva S Cunha
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles St, Baltimore, Maryland, 21218.,Department of Structural Biology, Max Plank Institute of Biophysics, Max-von-Laue-Str. 3, Frankfurt am Main, D-60438, Germany
| | - Christine L Hatem
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles St, Baltimore, Maryland, 21218
| | - Doug Barrick
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles St, Baltimore, Maryland, 21218
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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: 76] [Impact Index Per Article: 9.5] [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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50
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Güllert S, Fischer MA, Turaev D, Noebauer B, Ilmberger N, Wemheuer B, Alawi M, Rattei T, Daniel R, Schmitz RA, Grundhoff A, Streit WR. Deep metagenome and metatranscriptome analyses of microbial communities affiliated with an industrial biogas fermenter, a cow rumen, and elephant feces reveal major differences in carbohydrate hydrolysis strategies. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:121. [PMID: 27279900 PMCID: PMC4897800 DOI: 10.1186/s13068-016-0534-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/26/2016] [Indexed: 05/13/2023]
Abstract
BACKGROUND The diverse microbial communities in agricultural biogas fermenters are assumed to be well adapted for the anaerobic transformation of plant biomass to methane. Compared to natural systems, biogas reactors are limited in their hydrolytic potential. The reasons for this are not understood. RESULTS In this paper, we show that a typical industrial biogas reactor fed with maize silage, cow manure, and chicken manure has relatively lower hydrolysis rates compared to feces samples from herbivores. We provide evidence that on average, 2.5 genes encoding cellulolytic GHs/Mbp were identified in the biogas fermenter compared to 3.8 in the elephant feces and 3.2 in the cow rumen data sets. The ratio of genes coding for cellulolytic GH enzymes affiliated with the Firmicutes versus the Bacteroidetes was 2.8:1 in the biogas fermenter compared to 1:1 in the elephant feces and 1.4:1 in the cow rumen sample. Furthermore, RNA-Seq data indicated that highly transcribed cellulases in the biogas fermenter were four times more often affiliated with the Firmicutes compared to the Bacteroidetes, while an equal distribution of these enzymes was observed in the elephant feces sample. CONCLUSIONS Our data indicate that a relatively lower abundance of bacteria affiliated with the phylum of Bacteroidetes and, to some extent, Fibrobacteres is associated with a decreased richness of predicted lignocellulolytic enzymes in biogas fermenters. This difference can be attributed to a partial lack of genes coding for cellulolytic GH enzymes derived from bacteria which are affiliated with the Fibrobacteres and, especially, the Bacteroidetes. The partial deficiency of these genes implies a potentially important limitation in the biogas fermenter with regard to the initial hydrolysis of biomass. Based on these findings, we speculate that increasing the members of Bacteroidetes and Fibrobacteres in biogas fermenters will most likely result in an increased hydrolytic performance.
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Affiliation(s)
- Simon Güllert
- />Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany
| | - Martin A. Fischer
- />Institute for General Microbiology, Christian Albrecht University Kiel, Kiel, Germany
| | - Dmitrij Turaev
- />CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, Austria
| | - Britta Noebauer
- />CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, Austria
| | - Nele Ilmberger
- />Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany
| | - Bernd Wemheuer
- />Institute of Microbiology and Genetics, Georg-August-University Göttingen, Grisebachstr. 8, Göttingen, Germany
| | - Malik Alawi
- />Bioinformatics Core, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, Germany
- />Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistr. 52, Hamburg, Germany
| | - Thomas Rattei
- />CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, Austria
| | - Rolf Daniel
- />Institute of Microbiology and Genetics, Georg-August-University Göttingen, Grisebachstr. 8, Göttingen, Germany
| | - Ruth A. Schmitz
- />Institute for General Microbiology, Christian Albrecht University Kiel, Kiel, Germany
| | - Adam Grundhoff
- />Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistr. 52, Hamburg, Germany
| | - Wolfgang R. Streit
- />Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany
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