Purification and characterization of an extracellular lipase from a novel strain Penicillium sp. DS-39 (DSM 23773)

A newly isolated fungal strain, Penicillium sp. DS-39 (DSM 23773), was found to produce an inducible extracellular lipase when grown in a medium containing 1.0% (v/v) olive oil. Maximum lipase activity was obtained after 120 h of incubation at 28 °C. The lipase was purified 129-fold with a final specific activity of 308.73 IU/mg. The molecular weight of the homogeneous lipase was 43 kDa as determined by SDS-PAGE. It was optimally active at pH 5.5 and 45 °C. The lipase was most active on triolein and exhibited a broad substrate range with a preference for triacylglycerols containing long chain unsaturated fatty acids. It showed no regio-specificity for the ester bond in triolein. It was activated by Ca²⁺ and Mn²⁺, while significant inhibition was observed with Hg²⁺ and Zn²⁺. The lipase showed significant stability and activation in the presence of organic solvents with log P ≥ 2.0. These features render Penicillium sp. DS-39 lipase (PEL) a potential biocatalyst for applications such as biodiesel production, enzymatic restructuring, by interesterification of different oils and fats, and biodegradation of oil spills in the environment.