title: Burkholderia cepacia lipase is a promising biocatalyst for biofuel production.
abstract: Lipases resistant to inhibition and denaturation by methanol are valuable tools for biotechnological applications, in particular for biofuel production. Microbial lipases have attracted a great deal of interest because of their stability at high concentrations of organic solvents. Burkholderia cepacia lipase (BCL) is tested here for robustness towards methanol in terms of conformational stability and catalytic activity in transesterification assays. This lipase turns out to be even more tolerant than the homologous and better characterized enzyme from Burkholderia glumae. BCL unfolding transition, as monitored by far-UV circular dichroism (CD) and intrinsic fluorescence, displays a Tm above 60°C in the presence of 50% methanol. The protein unfolds at low pH, and the organic solvent affects the nature of the denatured state under acidic conditions. The protein performs well in transesterification assays upon prolonged incubations at high methanol concentrations. BCL is highly tolerant to methanol and displays particularly high conformational stability under conditions employed for transesterification reactions. These features depict BCL as a promising enzyme for biofuel industry.
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sasso
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Natalello
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Castoldi
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Lotti
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy. carlo.santambrogio@unimib.it.
authors.forename: Carlo
authors.initials: C
authors.lastname: Santambrogio
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy. rita.grandori@unimib.it.
authors.forename: Rita
authors.initials: R
authors.lastname: Grandori
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D055162:Biocatalysis; D056804:Biofuels; D016956:Burkholderia cepacia / Q000201:enzymology*; D002942:Circular Dichroism; D004789:Enzyme Activation; D004795:Enzyme Stability; D004951:Esterification; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D011487:Protein Conformation; D058767:Protein Unfolding
chemical_list: D001426:Bacterial Proteins; D056804:Biofuels; D008049:Lipase; D000432:Methanol
keywords: Biofuel; Circular dichroism; Conformational stability; Intrinsic fluorescence; Transesterification