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Title: Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities

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-typemore » cellulosomal system is necessary for this essential mode of action. As a result, 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.« less

Authors:
 [1];  [2];  [1];  [3];  [1];  [1];  [4];  [4];  [5];  [1]; ;  [4];  [4];  [5];  [6];  [1];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States); BioEnergy Science Center, Oak Ridge, TN (United States)
  2. BioEnergy Science Center, Oak Ridge, TN (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  4. BioEnergy Science Center, Oak Ridge, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. BioEnergy Science Center, Oak Ridge, TN (United States); Dartmouth College, Hanover, NH (United States)
  6. The Weizmann Institute of Science, Rehovot (Israel)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC)
Sponsoring Org.:
USDOE Office of Science (SC); USDOE Bioenergy Science Center (BESC)
OSTI Identifier:
1244830
Alternate Identifier(s):
OSTI ID: 1286890
Report Number(s):
NREL/JA-2700-65384
Journal ID: ISSN 2375-2548
Grant/Contract Number:  
AC36-08GO28308; AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Science Advances
Additional Journal Information:
Journal Volume: 2; Journal Issue: 2; Journal ID: ISSN 2375-2548
Publisher:
AAAS
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; cell biology; biomass; biofuels; cellulases; cellulosomes; 60 APPLIED LIFE SCIENCES

Citation Formats

Xu, Qi, Resch, Michael G., Podkaminer, Kara, Yang, Shihui, Baker, John O., Donohoe, Bryon S., Wilson, Charlotte, Klingeman, Dawn M., Olson, Daniel G., Decker, Stephen R., Richard J. Giannone, Hettich, Robert L., Brown, Steven D., Lynd, Lee R., Bayer, Edward A., Himmel, Michael E., and Bomble, Yannick J. Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities. United States: N. p., 2016. Web. doi:10.1126/sciadv.1501254.
Xu, Qi, Resch, Michael G., Podkaminer, Kara, Yang, Shihui, Baker, John O., Donohoe, Bryon S., Wilson, Charlotte, Klingeman, Dawn M., Olson, Daniel G., Decker, Stephen R., Richard J. Giannone, Hettich, Robert L., Brown, Steven D., Lynd, Lee R., Bayer, Edward A., Himmel, Michael E., & Bomble, Yannick J. Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities. United States. doi:10.1126/sciadv.1501254.
Xu, Qi, Resch, Michael G., Podkaminer, Kara, Yang, Shihui, Baker, John O., Donohoe, Bryon S., Wilson, Charlotte, Klingeman, Dawn M., Olson, Daniel G., Decker, Stephen R., Richard J. Giannone, Hettich, Robert L., Brown, Steven D., Lynd, Lee R., Bayer, Edward A., Himmel, Michael E., and Bomble, Yannick J. Fri . "Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities". United States. doi:10.1126/sciadv.1501254. https://www.osti.gov/servlets/purl/1244830.
@article{osti_1244830,
title = {Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities},
author = {Xu, Qi and Resch, Michael G. and Podkaminer, Kara and Yang, Shihui and Baker, John O. and Donohoe, Bryon S. and Wilson, Charlotte and Klingeman, Dawn M. and Olson, Daniel G. and Decker, Stephen R. and Richard J. Giannone and Hettich, Robert L. and Brown, Steven D. and Lynd, Lee R. and Bayer, Edward A. and Himmel, Michael E. and Bomble, Yannick J.},
abstractNote = {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. As a result, 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.},
doi = {10.1126/sciadv.1501254},
journal = {Science Advances},
number = 2,
volume = 2,
place = {United States},
year = {Fri Feb 05 00:00:00 EST 2016},
month = {Fri Feb 05 00:00:00 EST 2016}
}

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Cited by: 33 works
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Works referenced in this record:

Microbial Cellulose Utilization: Fundamentals and Biotechnology
journal, September 2002

  • Lynd, L. R.; Weimer, P. J.; van Zyl, W. H.
  • Microbiology and Molecular Biology Reviews, Vol. 66, Issue 3, p. 506-577
  • DOI: 10.1128/MMBR.66.3.506-577.2002

Biomass Recalcitrance: Engineering Plants and Enzymes for Biofuels Production
journal, February 2007

  • Himmel, M. E.; Ding, S.-Y.; Johnson, D. K.
  • Science, Vol. 315, Issue 5813, p. 804-807
  • DOI: 10.1126/science.1137016

High Ethanol Titers from Cellulose by Using Metabolically Engineered Thermophilic, Anaerobic Microbes
journal, September 2011

  • Argyros, D. Aaron; Tripathi, Shital A.; Barrett, Trisha F.
  • Applied and Environmental Microbiology, Vol. 77, Issue 23, p. 8288-8294
  • DOI: 10.1128/AEM.00646-11