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Title: In vivo synergistic activity of a CAZyme cassette from Acidothermus cellulolyticus significantly improves the cellulolytic activity of the C. bescii exoproteome

The use of microbial cells to convert plant biomass directly to fuels and chemicals is referred to as consolidated bioprocessing (CBP). Members of the bacterial genus, Caldicellulosiruptor (Gram-positive, anaerobic hyperthermophiles) are capable of deconstructing plant biomass without enzymatic or chemical pretreatment. This is accomplished by the production and secretion of free, multi-domain enzymes that outperform commercial enzyme cocktails on some substrates. Here, we show that the exoproteome of C. bescii may be enhanced by the heterologous expression of enzymes from Acidothermus cellulolyticus that act synergistically to improve sugar release from complex substrates; as well as improve cell growth. In this work, co-expression of the A. cellulolyticus Acel_0615 ..beta..-glucanase (GH6 and GH12) and E1 endoglucanase (GH5) enzymes resulted in an increase in the activity of the exoproteome on Avicel; as well as an increase in growth of C. bescii on Avicel compared to the parental strain or the strain expressing the ..beta..-glucanase alone. As a result, our ability to engineer the composition and effectiveness of the exoproteome of these bacteria provides insight into the natural mechanism of plant cell wall deconstruction, as well as future directions for improving CBP.
 [1] ;  [2] ;  [2] ;  [2] ; ORCiD logo [1]
  1. Univ. of Georgia, Athens, GA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0006-3592
Grant/Contract Number:
AC36-08GO28308; AC05-00OR22725
Accepted Manuscript
Journal Name:
Biotechnology and Bioengineering
Additional Journal Information:
Journal Volume: 114; Journal Issue: 11; Journal ID: ISSN 0006-3592
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
09 BIOMASS FUELS; Caldicellulosiruptior; biomass deconstruction; consolidated bioprocessing; glucanase
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1373813