title: Glycoside hydrolases from a targeted compost metagenome, activity-screening and functional characterization.
abstract: BACKGROUND
  Metagenomics approaches provide access to environmental genetic diversity for biotechnology applications, enabling the discovery of new enzymes and pathways for numerous catalytic processes. Discovery of new glycoside hydrolases with improved biocatalytic properties for the efficient conversion of lignocellulosic material to biofuels is a critical challenge in the development of economically viable routes from biomass to fuels and chemicals.
  
  
  RESULTS
  Twenty-two putative ORFs (open reading frames) were identified from a switchgrass-adapted compost community based on sequence homology to related gene families. These ORFs were expressed in E. coli and assayed for predicted activities. Seven of the ORFs were demonstrated to encode active enzymes, encompassing five classes of hemicellulases. Four enzymes were over expressed in vivo, purified to homogeneity and subjected to detailed biochemical characterization. Their pH optima ranged between 5.5 - 7.5 and they exhibit moderate thermostability up to ~60-70°C.
  
  
  CONCLUSIONS
  Seven active enzymes were identified from this set of ORFs comprising five different hemicellulose activities. These enzymes have been shown to have useful properties, such as moderate thermal stability and broad pH optima, and may serve as the starting points for future protein engineering towards the goal of developing efficient enzyme cocktails for biomass degradation under diverse process conditions.
authors: The Joint BioEnergy Institute, Emeryville, USA.
authors: Michael J
authors: MJ
authors: Dougherty
authors: Patrik
authors: P
authors: D'haeseleer
authors: Terry C
authors: TC
authors: Hazen
authors: Blake A
authors: BA
authors: Simmons
authors: Paul D
authors: PD
authors: Adams
authors: Masood Z
authors: MZ
authors: Hadi
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054892:Metagenome; D016366:Open Reading Frames; D012987:Soil; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D012987:Soil; D006026:Glycoside Hydrolases