Green Synthesis of Biodiesel Using Microbial Lipases

Abstract

Biodiesel, also called as fatty acid methyl esters (FAME), is a potential substitute to fossil-based diesel fuel owing to biodegradability, lesser toxicity, and reduced greenhouse gas emissions. Biodiesel is a renewable fuel and can be used in blended form or as direct substitute for petro-diesel in locomotive engines. Scientists are introducing many techniques for the biodiesel production and to convert the feedstock into biodiesel. Out of all the reported methods of conversion, transesterification has been the most preferred method. Currently, transesterification has been carried out by using chemical catalysts, i.e., acid and alkaline catalysts for which downstreaming becomes difficult and expensive. So enzymatic catalysts, i.e., microbial lipases, are preferred to cope with this problem. Moreover, different reaction conditions can be optimized to achieve highest yields of biodiesel. However, the biodiesel production cost is a little higher in comparison to fossil fuels which is a big hurdle in its commercialization. This problem can be solved by using immobilized microbial lipases as catalysts and nonconventional oils, i.e., algal and yeast oils as feedstocks for conversion into the biodiesel. Utilizing the nonconventional oils is also preferred because it will also reduce the clash between bioenergy and food production, also called as food vs fuel debate. The reason behind this debate is that many conventional food-based oils are utilized as feedstocks for the production of biodiesel. The utilization of lipase as biocatalyst after immobilization also gains huge attention as the synthesis of biodiesel is “greener.”