Optimization, characterization, and molecular modelling of an acid and organic solvent-tolerant lipase isolated from...

This research aimed to optimize, purify, and biochemically and structurally characterize an acid-stable and organic solvent-tolerant lipase from the fungus Monascus pilosus. Sequence alignment indicated that the fungus in this study exhibits a high similarity of 99.63 % with M. pilosus (NR 163510.1). Maximum lipase production (434.3 U/mL) was observed at pH 3 after five days of incubation at 30 °C. The structure analysis showed that the lipase belongs to the GXSXL family, and the Ser163, Asp224, and His250 residues construct the catalytic triad. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) estimated the molecular weight of lipase to be around 51 kDa. Maximum lipase activity was detected at pH 8 and 50 °C, recording an activity of 625.3 U/mL. This lipase is remarkably stable across a pH range of 1.5 to 9, with a 1.8-fold activity enhancement after 2-h of incubation at pH 1.5. The enzyme displayed considerable stability in chloroform, hexane, toluene, and dimethyl sulfoxide (DMSO), retaining over 85 % residual activity at a 10 % concentration. This novel acid and organic solvent-tolerant lipase can provide a sustainable solution for industrial detergent formulation and other environmentally friendly applications. This is the first report to isolate, purify, and characterize lipase from the genus Monascus.