Author(s): Ravindranath Tagore P1 and Lakshmi Narasu M2*
A fungal strain TL-12 was isolated from one hundred fifty fungal isolates obtained from oily soil samples. Initially fourteen isolates exhibited lipase activity and a promising strain TL-12 with extra-cellular lipase activity was identified as Aspergillus species and selected for further development. This strain was improved by physical and chemical mutagenesis to obtain a consistently high producer of extra-cellular lipase. UV, EMS and NTG methods were employed sequentially for the enhancement of extra cellular lipase production. Higher lipase producing UV mutants were subjected to EMS and then the higher lipase producing EMS mutants were further treated with NTG to obtain the high lipase yielding strain. The lipase activity increased up to 175%, 340% and 575% respectively, by UV, EMS and NTG treatments compared to the parent strain. The resulting improved strain labeled as Aspergillus TL-12(3) bears high potential for industrial applications. Lipase produced by this strain has a novel catalyzing activity to cleave the amide bond of penicillin G (benzyl penicillin) side chain to produce 6 amino penicillinic acid.