Conformation studies on Burkholderia cenocepacia lipase via resolution of racemic 1-phenylethanol in non-aqueous medium and its process optimization

In this study, the effect of various organic solvents on enzyme activity and substrate enantiomeric excess ( ee s ) of the lipase from Burkholderia cenocepacia (BCL) was investigated in the enantioselective transesterification of 1-phenylethanol. Secondary structure analysis by Fourier transform-infrared spectroscopy (FT-IR) showed that the variations in secondary structure element content (α-helix, β-sheet, β-turn and random coil) were probably responsible for the changes in enzyme activity and ee s . Furthermore, the change in fluorescence intensity indicated, to some extent, the alteration in tertiary structure, which may also explain why organic solvents affect enzyme activity and ee s . Moreover, response surface methodology (RSM) was employed to optimize the reaction parameters. The optimized reaction conditions were: substrate molar ratio 4.7:1; reaction time 18.6 h, and reaction temperature 53.4 °C. Under the optimal reaction conditions, the ee s and ee p were respectively 99.22% and 98.74%, and the corresponding enzyme activity was 1392.2 U/min/g protein. Compared with other lipases, BCL exhibited better catalytic efficiency and has significant potential in industrial applications.