Increasing the catalytic efficiency of Candida rugosa lipase for the synthesis of tert-alkyl butyrates in low-water media

Abstract

Reactions involving tert-alcohols and their esters are generally not catalyzed by lipases. Candida rugosa lipase is one of the few lipases which shows at least limited catalytic activity towards tert-alcohols and their esters. Using transesterification of tributyrin with tertiary butyl and amyl alcohols as a model reaction, it is shown that precipitation of lipase by a tertiary alcohol in the presence of a buffer with optimum concentration enhances the catalytic activity 7 fold as compared to rates obtained with lyophilized powders. Optimization of the ratio of triglyceride to tert-alcohols and medium engineering gave an initial rate which was 41 times higher than that obtained with lyophilized powders. Hence, use of a simple enzyme formulation, coupled with optimization of reaction conditions led to Candida rugosa lipase becoming a useful catalyst for catalyzing transesterification involving tertiary alcohols.

Keywords::

• Lipases
• transesterification
• tertiary alcohols
• enzyme catalysis in low water media
• tributyrin
• enzyme precipitated and rinsed with propanol

Acknowledgement

The work was supported by the “Core group grant for applied biocatalysis” Department of Science and Technology (DST), India. Additional financial supports from the funds obtained from the Department of Biotechnology (DBT), Govt. of India and UKIERI are also gratefully acknowledged.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.