title: Engineering Saccharomyces cerevisiae to produce feruloyl esterase for the release of ferulic acid from switchgrass.
abstract: The Aspergillus niger feruloyl esterase gene (faeA) was cloned into Saccharomyces cerevisiae via a yeast expression vector, resulting in efficient expression and secretion of the enzyme in the medium with a yield of ~2 mg/l. The recombinant enzyme was purified to homogeneity by anion-exchange and hydrophobic interaction chromatography. The specific activity was determined to be 8,200 U/μg (pH 6.5, 20°C, 3.5 mM 4-nitrophenyl ferulate). The protein had a correct N-terminal sequence of ASTQGISEDLY, indicating that the signal peptide was properly processed. The FAE exhibited an optimum pH of 6-7 and operated optimally at 50°C using ground switchgrass as the substrate. The yeast clone was demonstrated to catalyze the release of ferulic acid continuously from switchgrass in YNB medium at 30°C. This work represents the first report on engineering yeast for the breakdown of ferulic acid crosslink to facilitate consolidated bioprocessing.
authors.affiliation: Western Regional Research Center, USDA-ARS, Albany, CA, USA. Dominic.Wong@ars.usda.gov
authors.forename: Dominic W S
authors.initials: DW
authors.lastname: Wong
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Chan
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Batt
authors.forename: Gautam
authors.initials: G
authors.lastname: Sarath
authors.forename: Hans
authors.initials: H
authors.lastname: Liao
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002384:Catalysis; D003373:Coumaric Acids / Q000302:isolation & purification*; D009574:Nitro Compounds; D008897:Panicum / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: C546405:4-nitrophenyl ferulate; D003373:Coumaric Acids; D009574:Nitro Compounds; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase