title: An organic solvent-tolerant phenolic acid decarboxylase from Bacillus licheniformis for the efficient bioconversion of hydroxycinnamic acids to vinyl phenol derivatives.
abstract: A new phenolic acid decarboxylase gene (blpad) from Bacillus licheniformis was cloned and overexpressed in Escherichia coli. The full-length blpad encodes a 166-amino acid polypeptide with a predicted molecular mass and pI of 19,521 Da and 5.02, respectively. The recombinant BLPAD displayed maximum activity at 37 °C and pH 6.0. This enzyme possesses a broad substrate specificity and is able to decarboxylate p-coumaric, ferulic, caffeic, and sinapic acids at the relative ratios of specific activities 100:74.59:34.41:0.29. Kinetic constant K m values toward p-coumaric, ferulic, caffeic, and sinapic acids were 1.64, 1.55, 1.93, and 2.45 mM, and V max values were 268.43, 216.80, 119.07, and 0.78 U mg(-1), respectively. In comparison with other phenolic acid decarboxylases, BLPAD exhibited remarkable organic solvent tolerance and good thermal stability. BLPAD showed excellent catalytic performance in biphasic organic/aqueous systems and efficiently converted p-coumaric and ferulic acids into 4-vinylphenol and 4-vinylguaiacol. At 500 mM of p-coumaric and ferulic acids, the recombinant BLPAD produced a total 60.63 g l(-1) 4-vinylphenol and 58.30 g l(-1) 4-vinylguaiacol with the conversion yields 97.02 and 70.96 %, respectively. The low yield and product concentration are the crucial drawbacks to the practical bioproduction of vinyl phenol derivatives using phenolic acid decarboxylases. These unusual properties make BLPAD a desirable biocatalyst for commercial use in the bioconversion of hydroxycinnamic acids to vinyl phenol derivatives via enzymatic decarboxylation in a biphasic organic/aqueous reaction system.
authors.affiliation: Department of Biological Engineering, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Hu
authors.forename: Lulu
authors.initials: L
authors.lastname: Li
authors.forename: Shaojun
authors.initials: S
authors.lastname: Ding
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001711:Biotransformation; D002262:Carboxy-Lyases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003373:Coumaric Acids / Q000378:metabolism*; D004795:Enzyme Stability; D007700:Kinetics; D010636:Phenols / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D003373:Coumaric Acids; D010636:Phenols; D002262:Carboxy-Lyases; C417714:phenolic acid decarboxylase; C030626:4-vinylphenol