Bioremediation of waste cooking oil using a novel lipase produced by Penicillium chrysogenum SNP5 grown in solid medium containing waste grease

The aim of present work was to bioremediate the waste cooking oil using a novel lipase produced in solid medium containing waste grease and wheat bran by Penicillium chrysogenum. Enzyme extracted with phosphate buffer was purified 10.6 and 26.28-fold after 90% ammonium sulfate precipitation and ion-exchange chromatography, respectively. The partial characterization of enzyme revealed its Km and Vmax value for p-nitrophenolpamitate as 0.4 mM and 47.61 U/ml, respectively. The relative molecular mass of lipase was 40 kDa by SDS–PAGE and confirmed by zymogram. Purified lipase was most stable at 40 °C and at 8.0 pH. Lipase activity was enhanced by metal ions such as Mg2+, Fe2+, Ca2+ and non-ionic surfactant TritonX-100, while suppressed in the presence of SDS. Crude lipase was applied on cooking oil waste and the acid value was 26.92 mg/g. This showed that the enzyme could be employed for the bioremediation of used cooking oil.

► Lipase was found novel because of its low Km value 0.4 mM and high Vmax 47.61 U/ml with high specificity for used cooking oil.
► Lipase was purified up to single band with the help of ion exchange chromatography and confirmed through zymogram.
► Lipase released significant amount of free fatty acid content from used cooking oil measured as acid values 26.92 mg/g confirmed its specificity.