Isolation and Screening of Extracellular Lipase Producing Fungi From Soil

Microbial lipases (extracellular in origin) are the most broadly utilized industrial enzymes. Some industries (detergent, food, oil and paper) demand for lipolytic microbes to fulfill several applications. Therefore, identification and isolation of lipolytic fungi from soil is very significant for such industries. Soil is the best habitat for several microorganisms, secreting enzymes of extracellular origin thus soil samples were obtained from five diverse oil mills of Newai town and were utilized in the current study. Soil samples were processed by serial dilution agar plate method for the isolation of fungi in PDA (Potato dextrose agar) plates. Isolated fungi were further qualitatively evaluated for extracellular lipase production on tributyrin agar (TBA) medium. Lipolytic activity was identified by the formation of halo zone (clear zone of tributyrin degradation) around colonies of fungi. Formation of clear zone around the colonies indicated the production of extracellular lipase, which hydrolyzed the tributyrin and opacity of the medium around such colonies was not retained. Among the all tested thirty one fungal isolates for extracellular lipase production in TBA media, twelve isolates demonstrated zone of hydrolysis. Based on the interpretation of primary screening, four fungal isolates (LPF-5, LPF-9, LPF-17 and LPF-28) were further confirmed for extracellular lipase production in SmF using quantitative method. Among the four isolates, Maximum lipase production (82.21 ± 0.90 U mL-1 min-1) was obtained by isolate LPF-5 at 72 h of incubation at 28 ºC. Key words: Lipase, lipolytic microbes, tributyrin agar medium, zone of hydrolysis, quantitative assay