Production of extracellular lipase by a new strain Staphylococcus aureus NK-LB37 isolated from oil contaminated soil

Abstract

A total of 20 bacterial isolates were obtained by screening using tributyrin agar medium. Among them the isolate which exhibited greater clearance zone and higher lipase activity was subsequently screened using spirit blue agar and rhodamine B agar medium. Based on morphological, biochemical and 16S rRNA sequence analysis, the potent isolate was identified as Staphylococcus aureus. The lipase production of the isolate was increased by improving the conditions of production medium. Maximum lipase production (8.11 U/ml) was achieved  when 2%  punnakka oil was utilized as sole carbon source at pH 7.0 and 37°C after 2 days of incubation. Addition of  3% tryptone as nitrogen source and 0.01% MgCl₂  resulted in a significant increase of lipase production (10.73 U/ml). The lipase production was slightly enhanced in the presence of 20%  n-propanol and highly stable in the presence of n-butanol, toluene and n-hexane. The study resulted in isolation and production of  inducible,  mesophilic and solvent tolerant lipase with industrial potential.

Keywords:  Staphylococcussp.,  tributyrin agar, 16S rRNA , medium optimization, solvent-tolerant lipase.

African Journal of Biotechnology, Vol 13(28) 2858-2866