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Title: Engineering the N-terminal end of CelA results in improved performance and growth of Caldicellulosiruptor bescii on crystalline cellulose

Here, CelA is the most abundant enzyme secreted by Caldicellulosiruptor bescii and has been shown to outperform mixtures of commercially available exo- and endoglucanases in vitro. CelA contains both a glycoside hydrolase family 9 endoglucanase and a glycoside hydrolase family 48 exoglucanase known to be synergistic in their activity, connected by three cellulose-binding domains via linker peptides. Here, repeated aspartate residues were introduced into the N-terminal ends of CelA GH9 and GH48 domains to improve secretion efficiency and/or catalytic efficiency of CelA. Among several constructs, the highest activity on carboxymethylcellulose (CMC), 0.81 ± 0.03 mg/mL was observed for the C. bescii strain containing CelA with 5-aspartate tag at the N-terminal end of GH9 domain – an 82% increase over wild type CelA. In addition, Expression of CelA with N-terminal repeated aspartate residues in C. bescii results in a dramatic increase in its ability to grow on Avicel.
 [1] ;  [2] ;  [2] ;  [2] ;  [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: 5; 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; biomass deconstruction; CelA; repeated aspartate residues; Caldicellulosiruptior
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1401885