Screening of thermophilic neutral lipase-producing Pseudomonas sp. ZBC1 and improving its enzymatic activity

Abstract

From oil-contaminated soil, three lipase-producing microorganisms were selected as good lipase producers using rhodamine B-olive oil plate agar and they were identified as from Pseudomonas, Burkholderia and Klebsiella genera by morphology, biochemical characterization and 16S rRNA gene sequencing. Among the three strains, Pseudomonas sp. ZBC1 was found to produce thermophilic neutral lipase which exhibited maximum activity at 80oC and pH 7.0. Plackett-Burman design (PB design) and response surface methodology (RSM) analysis showed that the optimum values of the most significant factors are MgSO4 (0.85 g/L), inoculum size (65.9 ml/L) and volume of medium (51.57 ml). Under the optimal conditions, lipase production by Pseudomonas sp. ZBC1 was enhanced by approximately 2.30 fold (from 8.50 to 19.50 U/ml). Keywords : Pseudomonas , lipase, thermophilic, response surface methodology African Journal of Biotechnology Vol. 12(9), pp. 949-957