Production of marine microalgal biodiesel through interesterification using novel Bacillus lipase

In this study, enzymatic interesterification is carried out using encapsulated lipase as biocatalyst with methyl acetate as acyl acceptor in a solvent free system. Lipase, isolated from a marine bacterial isolate. Bacillus sp.S23 (KF220659.1) was immobilized in a sodium alginate beads. This investigation elaborated on the effects of various parameters namely enzyme loading, temperature, water, molar ratio, reaction time and agitation for interesterification. The study resulted in the following optimal conditions- 1.5 g immobilised lipase, 1:12 molar ratio of oil to methyl acetate, 35 °C, 8 % water, 60 h reaction time, 250 rpm of agitation. With the standardized condition, the maximum conversion efficiency was 95.68%. The immobilized beads, even after 10 cycles of repeated usage showed high stability in the presence of methyl acetate and no loss of lipase activity. The microalgal biodiesel composition was analysed by Gas Chromatography. The current study was efficient in using immobilized lipase for interesterification process, as the method turned to be cost effective and ecofriendly, no solvent was involved and enzyme being encapsulated in a natural polymer.