title: Molecular cloning, overexpression and characterization of a novel feruloyl esterase from a soil metagenomic library.
abstract: The gene estF27, encoding a protein with feruloyl esterase activity, was cloned through functional screening from a soil metagenomic library and expressed in Escherichiacoli BL21 (DE3) with high solubility. Sequence analysis showed that estF27 encoded a protein of 291 amino acids with a predicted molecular mass of 31.16 kDa. According to the substrate specificity, EstF27 was classified as a type A feruloyl esterase. EstF27 displayed optimal activity at 40°C and pH 6.8. This enzyme was stable in a broad pH range of 5.0-10.0 over 24 h, and retained more than 50% of its activity after 96 or 120 h incubation in the presence of 3 M KCl or 5 M NaCl. The enzyme activity was slightly enhanced by the addition of Mg(2+) and Fe(3+) at a low concentration, and completely inhibited by Cu(2+). In the enzymatic hydrolysis of destarched wheat bran, EstF27 could release ferulic acid from it in the presence of xylanase from Thermomyces lanuginosus. Given its alkalitolerance, halotolerance and highly soluble expression, EstF27 is a promising candidate for industrial applications.
authors.affiliation: State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Shu Li
authors.initials: SL
authors.lastname: Sang
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Xiao Peng
authors.initials: XP
authors.lastname: Hu
authors.forename: Yu Huan
authors.initials: YH
authors.lastname: Liu
mesh_terms: D001709:Biotechnology / Q000379:methods; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D003373:Coumaric Acids / Q000378:metabolism; D004043:Dietary Fiber / Q000378:metabolism; D004795:Enzyme Stability; D005786:Gene Expression Regulation; D006863:Hydrogen-Ion Concentration; D056186:Metagenomics; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013379:Substrate Specificity; D015854:Up-Regulation
chemical_list: D003373:Coumaric Acids; D004043:Dietary Fiber; D011994:Recombinant Proteins; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase