title: Engineering broad-spectrum digestion of polyuronides from an exolytic polysaccharide lyase.
abstract: BACKGROUND
  Macroalgae represents a promising source of fermentable carbohydrates for use in the production of energy efficient biofuel. The primary carbohydrate in brown algae is the uronic acid-containing alginate, whereas green algae contains a significant amount of glucuronan. A necessary step in the conversion of these polyuronides to bioethanol is saccharification, which can be achieved by enzymatic or chemical degradation.
  
  
  RESULTS
  Polysaccharide lyases are a class of enzymes which cleave uronic acid-containing glycans via a β-elimination mechanism, acting both endo- and exolytically on their substrates. In the present work, we characterize a putative alginate lyase from Stenotrophomonas maltophilia K279a (Smlt2602) and describe a H208F mutant that, in addition to cleaving alginate-based substrates, displays significant, exolytic glucuronan activity.
  
  
  CONCLUSIONS
  To our knowledge this is the first polysaccharide lyase to act exolytically on glucuronan and is an attractive candidate for the broad-spectrum digestion of polyuronides into fermentable monomers.
authors.affiliation: Program in Bioengineering, Lehigh University, B320 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 USA.
authors.forename: Logan C
authors.initials: LC
authors.lastname: MacDonald
authors.affiliation: Program in Bioengineering, Lehigh University, B320 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 USA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Weiler
authors.affiliation: Program in Bioengineering, Lehigh University, B320 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 USA ; Department of Chemical and Biomolecular Engineering, Lehigh University, B320 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 USA.
authors.forename: Bryan W
authors.initials: BW
authors.lastname: Berger
keywords: Alginate; Alginate lyase; Polysaccharide; Stenotrophomonas maltophilia; Uronic acid