[Screening and identification of a strain with lipolytic activity against Jatropha oil and its catalytic capacity].

ABSTRACT

OBJECTIVE: To screen lipases applied to biodiesel production, a lipase-producing microorganism was isolated and the enzyme was characterized. METHODS: A strain with lipolytic activity against Jatropha oil was isolated from the soil pretreated by Jatropha curcas L. seed and cultivated on Jatropha oil as sole carbon source. The organic solvent tolerance of the isolated strain and its lipase were measured. The esterification and transesterification catalyzed by the isolated lipase were surveyed. The isolated strain was identified according to the physiological and biochemical characteristics as well as 16S rDNA sequences analysis. RESULTS: The lipolytic activity of the strain LP-2 was 3.03 U/mL. The relative biomass of strain LP-2 in the media containing 5% (v/v) methanol was 87.3%. The residual activity of LP-2 lipase in 10% (v/v) hexane was 80.9%. LP-2 lipase could catalyze esterification between lauric acid or palmitic acid and n-butanol, n-octanol, dodecanol or glycerol; stearic acid and n-octanol, dodecanol or glycerol; oleic acid and methanol, n-butanol, n-octanol or dodecanol. The transesterification of Jatropha oil with methanol could be catalyzed by LP-2 lipase. Strain LP-2 was identified as Staphylococcus epidermidis and named Staphylococcus epidermidis LP-2. CONCLUSION: S. epidermidis LP-2 lipase had the ability to catalyze esterification and transesterification reactions, which suggested that it had potential of producing biodiesel.