Energy assessment and enhancement of the lipid yield of indigenous Chlorella sp KA-24NITD using Taguchi approach

A major step in microalgal biodiesel production is lipid extraction, which is mostly done using the conventional chloroform-methanol solvent system. The objective of the present work was to optimise the process of pretreatment of an indigenous Chlorella sp. KA-24NITD (Chl-24). Various physical cell disruption methods were combined with the optimised solvent system along with chemical (Dimethyl sulfoxide) and enzymatic (cellulase and pectinase) pretreatments of wet and dry biomass for lipid yield enhancement. Optimisation was done by Taguchi Orthogonal Array L9 (3(4)). Under optimised conditions, subsequent experimental runs showed that the optimum lipid yield of about 38.59% was obtained when wet biomass was enzymatically pretreated with pectinase and cellulase in the ratio 1:2 along with the combination of the physical process. Thus enzymatic pretreatment proved to be more efficient than chemical pretreatment showing significant results by improving lipid yield, which suggests that Chl-24 could be a potent candidate for biodiesel production. (C) 2018 Elsevier Ltd. All rights reserved.