Biodiesel synthesis and conformation of lipase from Burkholderia cepacia in room temperature ionic liquids and organic solvents

Biodiesel synthesis and conformation of Burkholderia cepacia lipase (BCL) were studied in 19 different room temperature ionic liquids (RTLLs) with a range of cation and anion structures. Overall, anion selection had a greater influence on biodiesel conversion than cation choice. RTILs containing Tf(2)N(-)and PF6- anions were suitable reaction media, while RTIL of [OmPy] [BE4] was the best reaction medium with a biodiesel yield of 82.2 +/- 1.2%. RTILs with strong water miscible properties showed very low biodiesel yields. Conformational analysis by FT-IR revealed that higher biodiesel conversion in RTILs was correlated with a low tendency in alpha-helix content of BCL. An ultrasound-assisted biocatalysis process in RTILs was used to improve mass transfer rate, leading to 83% reduction of the reaction time for biodiesel production. (C) 2011 Elsevier Ltd. All rights reserved.