Enzymatic transesterification of coconut oil by using immobilized lipase on biochar: An experimental and molecular docking study

Guava seed biochar appears as a new alternative of the effective support to the immobilization ofBurkholderia cepacialipase (BCL) by physical adsorption. The objective of this work was to evaluate the potential of this immobilized biocatalyst in the transesterification reaction of crude coconut oil and ethanol and to understand the mechanism of the reaction through the study of molecular docking. The best loading of BCL was determined to be 0.15 g(enzyme)/g(support)having a hydrolytic activity of 260 U/g and 54% immobilization yield. The products of transesterification reaction produced a maximum yield at 40 degrees C under different reaction conditions. The monoacylglycerols (MAGs) conversion of 59% was using substrate molar ratio oil:ethanol of 1:7 with the reaction time of 24 H. In addition, the highest ethyl esters yield (48%) had the molar ratio of 1:7 with the reaction time of 96 H and maximum conversion of diacylglycerols (DAGs) was 30% with the molar ratio of 1:6 with the reaction time of 24 H. Molecular Docking was applied to clarify the mechanisms of transesterification reaction at the molecular level. MAGs and DAGs are compounds with excellent emulsifying properties used in industrial production of several bioproducts such as cosmetic, pharmaceuticals, foods, and lubricants.

Automated summary

The study demonstrated that guava seed biochar can serve as an effective support for Burkholderia cepacia lipase (BCL) in the transesterification reaction of crude coconut oil and ethanol, with the optimal condition of enzyme loading of 0.15 g/g at 40 degrees Celsius for 24 hours, which yielded the highest conversion rate.