Isolation and selection of lipolytic enzymes-producing fungi

Abstract

This study aims at isolating and selecting the lipolytic enzymes-producing microorganisms, and at assessing its effect on different substrates. The enzyme production was performed by solid state fermentation with wheat bran for 120 hours of incubation at 35 °C and 50% moisture. The lipase activity was measured by titration using a reaction system consisted of 4 mL of 50 mM acetate buffer, pH 5.6, 1 g of substrate and 1 mL of crude enzyme extract. One unit of enzyme activity was defined as the amount of enzyme required to liberate 1 μmole of fatty acid. The substrates were dairy cream, soybean oil and coconut fat. Thirty-three fungi strains were isolated, which were separated into four groups (A, B, C and D) according to enzymatic extracts. The group C showed the highest values for lipase activity, which were 10.41 and 9.49 μmole/mL in dairy cream, 8.96 and 7.51 μmole/mL in soybean oil and 8.52 and 8.14 μmole/mL in coconut fat. The assay employed in this study showed to be an effective technique for isolating filamentous fungi with high lipolytic activity. Study on fungi lineages and isolates wiL be crucial for biotechnology purposes.