The Engineering of Photobacterium Lipolyticum M37 Lipase to Increase Catalytic activity for Efficient Production of Biodiesel

Lipases represent a versatile class of biocatalysts with numerous potential applications in industry, including the production of biodiesel via enzyme-catalyzed transesterification.  Nevertheless, relatively slow enzyme reaction rates caused by poor interaction between lipase and lipid hinder the utilization of lipases for industrial biodiesel production. For these reasons, several approaches have been used in attempts to improve lipase functions. For example, modified lipase reaction conditions and enzyme immobilization represent indirect alternatives to the development of modified lipases, but these approaches have not yet produced sufficient improvements. Alternatively, new lipases have been sought using metagenomics, but this approach has had no noteworthy achievements. To improve the activity of lipases and their substrate specificity, thermal resistance, and stability, extensive studies have been done in which structural data from X-ray crystallography of various lipases have been used to identify key residues in the active site and surrounding areas. The lipases were then modified using protein-engineering techniques such as site-directed mutagenesis. Although this approach has improved lipase activity, the change is not substantial enough for industrial applications. Here, we designed a super lipase using the photobacterium lipolyticum M37 lipase as a template scaffold. We tested its performance with a series of esters as well as triglycerides. Compared with wild-type lipase, the engineered M37 lipase showed consistently higher catalytic activity and substantially reduced the biodiesel production time.  Therefore, our results suggest that our novel approaches represent a useful platform technology for the production of biodiesel, as well as for biochemicals that utilize hydrophobic substrates in industry.