Lignocellulosic Biomass Deconstruction by the Extremely Thermophilic Genus Caldicellulosiruptor
Jonathan M. Conway, Jeffrey V. Zurawski, Laura L. Lee, Sara E. Blumer-Schuette and Robert M. Kelly
from: Thermophilic Microorganisms (Edited by: Fu-Li Li). Caister Academic Press, U.K. (2015) Pages: 91-120.
Extremely thermophilic bacteria from the genus Caldicellulosiruptor produce a variety of large multi-domain proteins for the attachment to and degradation of lignocellulosic biomass. The currently sequenced genomes from the genus Caldicellulosiruptor encode 144 homologous groups of Carbohydrate Active enZymes (CAZymes) containing 128 glycoside hydrolase (GH), 58 carbohydrate binding module (CBM), 9 polysaccharide lyase (PL), and 11 carbohydrate esterase (CE) domains. Extracellular CAZymes from these species have a distinct multi-domain architecture, with multiple catalytic and binding domains in the same protein. This promotes synergy between catalytic domains and enhances the ability of these bacteria to degrade biomass. A number of these extracellular multi-domain proteins are also cell surface associated via surface layer homology (SLH) domains. These SLH domain-containing proteins are thought to help these species attach to the biomass substrate, while catalytic domains in the same proteins degrade it. Because of their highly effective biomass degradation strategy, Caldicellulosiruptor species are of particular interest for development into consolidated bioprocessing microorganisms for the processing of lignocellulosic biomass to biofuels read more ...