title: Engineering microbial surfaces to degrade lignocellulosic biomass.
abstract: Renewable lignocellulosic plant biomass is a promising feedstock from which to produce biofuels, chemicals, and materials. One approach to cost-effectively exploit this resource is to use consolidating bioprocessing (CBP) microbes that directly convert lignocellulose into valuable end products. Because many promising CBP-enabling microbes are non-cellulolytic, recent work has sought to engineer them to display multi-cellulase containing minicellulosomes that hydrolyze biomass more efficiently than isolated enzymes. In this review, we discuss progress in engineering the surfaces of the model microorganisms: Bacillus subtilis, Escherichia coli, and Saccharomyces cerevisiae. We compare the distinct approaches used to display cellulases and minicellulosomes, as well as their surface enzyme densities and cellulolytic activities. Thus far, minicellulosomes have only been grafted onto the surfaces of B. subtilis and S. cerevisiae, suggesting that the absence of an outer membrane in fungi and Gram-positive bacteria may make their surfaces better suited for displaying the elaborate multi-enzyme complexes needed to efficiently degrade lignocellulose.
authors.affiliation: Department of Chemistry and Biochemistry; University of California-Los Angeles; Los Angeles, CA USA; UCLA-DOE Institute of Genomics and Proteomics; University of California-Los Angeles; Los Angeles, CA USA.
authors.forename: Grace L
authors.initials: GL
authors.lastname: Huang
authors.affiliation: Department of Chemistry and Biochemistry; University of California-Los Angeles; Los Angeles, CA USA; UCLA-DOE Institute of Genomics and Proteomics; University of California-Los Angeles; Los Angeles, CA USA.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Anderson
authors.affiliation: Department of Chemistry and Biochemistry; University of California-Los Angeles; Los Angeles, CA USA; UCLA-DOE Institute of Genomics and Proteomics; University of California-Los Angeles; Los Angeles, CA USA; Molecular Biology Institute; University of California-Los Angeles; Los Angeles, CA USA.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Clubb
mesh_terms: D018407:Bacterial Physiological Phenomena; D057005:Bioengineering / Q000379:methods; D056804:Biofuels / Q000382:microbiology*; D002462:Cell Membrane / Q000502:physiology*; D044602:Cellulases / Q000502:physiology*; D044603:Cellulosomes / Q000378:metabolism*; D003247:Conservation of Natural Resources; D024861:Genetic Enhancement / Q000379:methods*; D008031:Lignin / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods
chemical_list: D056804:Biofuels; C036909:lignocellulose; D008031:Lignin; D044602:Cellulases
keywords: Bacillus subtilis; Escherichia coli; Saccharomyces cerevisiae; biofuels; cell surface display; cellulase; consolidated bioprocessing; lignocellulose; minicellulosome