Extracellular Alkaline Lipase from a Novel Fungus sp. DHE 5: Optimisation of Physicochemical Parameters, Partial Purification and Characterisation.

Thirty isolated fungal strains were screened for lipase production using Phenol Red plates, containing tributyrin as lipidic substrate, and a novel fungus identified genetically as sp. DHE 5 was found as the most prominent strain. Various agro-industrial substrates were evaluated as inert supports for lipase production in solid-state fermentation. The highest yield of lipase ((83.4±2.2) U/g on dry mass basis) was reported with wheat bran medium after seven days of fermentation at pH=7.0, temperature of 30 °C, 70% moisture content, inoculum size of 1.27·10 spore/mL and 2% olive oil as an inducer. Supplementation of the medium with 0.05% KCl as an ion source further increased lipase production to (88.9±1.2) U/g on dry mass basis. The enzyme was partially purified through ammonium sulphate fractionation (40%) followed by dialysis, and its optimum pH and temperature were reported at 8.0 and 50 °C, respectively, with remarkable pH and thermal stability.