Partial purification and characterization acidophilic lipase from Bacillus cereus ALP E1.

The discovery of a new microbial lipase is crucial since its utilization has various industrial applications. Bacillus cereus is a strain that has emerged as a potential source of microbial lipase. Until now, the exploration of new lipases from Bacillus cereus remains limited. This study aims to obtain a lipase enzyme from Bacillus cereus ALP E1, as well as to purify and characterize the lipase produced by this strain. In this study, an extracellular acidophilic lipase from Bacillus cereus ALP E1 isolated from seawater at Panjang Port, Lampung, Indonesia was partially purified and characterized. Extracellular lipase was produced using submerged fermentation methods, and then partially purified with ammonium sulphate fractionation and dialysis. Partial purification successfully achieved a 12.31 purification fold with specific activity at 31083.14 U/mg. According to SDS-PAGE analysis, the purified lipase had a single dominant band estimated at 55 kDa. Lipase characterization revealed an optimal pH of 5, an optimal temperature of 40 °C, and the highest activity towards the substrate p-nitrophenyl stearate (C18). The lipase was activated by Ba2+ and deactivated by Mg2+. This lipase activity is enhanced by adding 1 % Tween 20, but it is deactivated by Tween 80. All tested organic solvents at 5 % concentration were able to activate the lipase with the optimized two-fold lipase activation using chloroform added. The results demonstrate that seawater is a promising source for discovering lipases with high activity. This complete characterization is important information and serves as a foundation for using lipase in appropriate industrial applications.