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Title: Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization

Abstract

Microbiological, genomic and transcriptomic analyses were used to examine three species from the bacterial genus Caldicellulosiruptor with respect to their capacity to convert the carbohydrate content of lignocellulosic biomass at 70 degrees C to simple sugars, acetate, lactate, CO2, and H-2. Caldicellulosiruptor bescii, C. kronotskyensis, and C. saccharolyticus solubilized 38%, 36%, and 29% (by weight) of unpretreated switchgrass (Panicum virgatum) (5 g/liter), respectively, which was about half of the amount of crystalline cellulose (Avicel; 5 g/liter) that was solubilized under the same conditions. The lower yields with C. saccharolyticus, not appreciably greater than the thermal control for switchgrass, were unexpected, given that its genome encodes the same glycoside hydrolase 9 (GH9)-GH48 multidomain cellulase (CelA) found in the other two species. However, the genome of C. saccharolyticus lacks two other cellulases with GH48 domains, which could be responsible for its lower levels of solubilization. Transcriptomes for growth of each species comparing cellulose to switchgrass showed that many carbohydrate ABC transporters and multidomain extracellular glycoside hydrolases were differentially regulated, reflecting the heterogeneity of lignocellulose. However, significant differences in transcription levels for conserved genes among the three species were noted, indicating unexpectedly diverse regulatory strategies for deconstruction for these closely related bacteria. Genesmore » encoding the Che-type chemotaxis system and flagellum biosynthesis were upregulated in C. kronotskyensis and C. bescii during growth on cellulose, implicating motility in substrate utilization. The results here show that capacity for plant biomass deconstruction varies across Caldicellulosiruptor species and depends in a complex way on GH genome inventory, substrate composition, and gene regulation.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [2];  [3];  [1]
  1. North Carolina State Univ., Raleigh, NC (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Univ. of Georgia, Athens, GA (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1335326
DOE Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied and Environmental Microbiology; Journal Volume: 81; Journal Issue: 20
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Zurawski, Jeffrey V., Conway, Jonathan M., Lee, Laura, Simpson, Hunter, Izquierdo, Javier, Blumer-Schuette, Sara E., Nookaew, Intawat, Adams, Michael W. W., and Kelly, Robert M. Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization. United States: N. p., 2015. Web. doi:10.1128/AEM.01622-15.
Zurawski, Jeffrey V., Conway, Jonathan M., Lee, Laura, Simpson, Hunter, Izquierdo, Javier, Blumer-Schuette, Sara E., Nookaew, Intawat, Adams, Michael W. W., & Kelly, Robert M. Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization. United States. doi:10.1128/AEM.01622-15.
Zurawski, Jeffrey V., Conway, Jonathan M., Lee, Laura, Simpson, Hunter, Izquierdo, Javier, Blumer-Schuette, Sara E., Nookaew, Intawat, Adams, Michael W. W., and Kelly, Robert M. Fri . "Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization". United States. doi:10.1128/AEM.01622-15.
@article{osti_1335326,
title = {Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization},
author = {Zurawski, Jeffrey V. and Conway, Jonathan M. and Lee, Laura and Simpson, Hunter and Izquierdo, Javier and Blumer-Schuette, Sara E. and Nookaew, Intawat and Adams, Michael W. W. and Kelly, Robert M.},
abstractNote = {Microbiological, genomic and transcriptomic analyses were used to examine three species from the bacterial genus Caldicellulosiruptor with respect to their capacity to convert the carbohydrate content of lignocellulosic biomass at 70 degrees C to simple sugars, acetate, lactate, CO2, and H-2. Caldicellulosiruptor bescii, C. kronotskyensis, and C. saccharolyticus solubilized 38%, 36%, and 29% (by weight) of unpretreated switchgrass (Panicum virgatum) (5 g/liter), respectively, which was about half of the amount of crystalline cellulose (Avicel; 5 g/liter) that was solubilized under the same conditions. The lower yields with C. saccharolyticus, not appreciably greater than the thermal control for switchgrass, were unexpected, given that its genome encodes the same glycoside hydrolase 9 (GH9)-GH48 multidomain cellulase (CelA) found in the other two species. However, the genome of C. saccharolyticus lacks two other cellulases with GH48 domains, which could be responsible for its lower levels of solubilization. Transcriptomes for growth of each species comparing cellulose to switchgrass showed that many carbohydrate ABC transporters and multidomain extracellular glycoside hydrolases were differentially regulated, reflecting the heterogeneity of lignocellulose. However, significant differences in transcription levels for conserved genes among the three species were noted, indicating unexpectedly diverse regulatory strategies for deconstruction for these closely related bacteria. Genes encoding the Che-type chemotaxis system and flagellum biosynthesis were upregulated in C. kronotskyensis and C. bescii during growth on cellulose, implicating motility in substrate utilization. The results here show that capacity for plant biomass deconstruction varies across Caldicellulosiruptor species and depends in a complex way on GH genome inventory, substrate composition, and gene regulation.},
doi = {10.1128/AEM.01622-15},
journal = {Applied and Environmental Microbiology},
number = 20,
volume = 81,
place = {United States},
year = {Fri Aug 07 00:00:00 EDT 2015},
month = {Fri Aug 07 00:00:00 EDT 2015}
}