Acidic–alkaline ferulic acid esterase from Chaetomium thermophilum var. dissitum: Molecular cloning and characterization of recombinant enzyme expressed in Pichia pastoris. (January 2016) - Dotsenko, Gleb
Abstract: A novel ferulic acid esterase encoding gene CtFae, was successfully cloned from a highly esterase active strain of the thermophile ascomycetous fungus Chaetomium thermophilum var. dissitum ; the gene was heterologously expressed in Pichia pastoris KM71H. The recombinant enzyme (CtFae) was purified to homogeneity and subsequently characterized. CtFae was active towards synthetic esters of ferulic, p-coumaric, and caffeic acids, as well as towards wide range of p-nitrophenyl substrates. Its temperature and pH optima were 55 °C and pH 6.0, respectively. Enzyme rare features were broad pH optimum, high stability at extended acidic–alkaline pH region, and noticeable thermostability. CtFae released ferulic acid from wheat insoluble arabinoxylan, as well as ferulic and p-coumaric acids from wheat straw and ryegrass, indicating potentials for industrial applications like biomass conversion in biorefineries. Highlights: A novel C. thermophilum ferulic acid esterase encoding gene was cloned and expressed. The recombinant enzyme (CtFae) was purified and subsequently characterized. CtFae rare features were broad pH optimum and high stability at acidic–alkaline pH. CtFae was able to release ferulic and p-coumaric acids from natural biomass. CtFae is a promising enzyme for practical application.