Enhanced production of extracellular lipase by ethyl methane sulfonate from soil fungal strain in submerged and solid-state fermentation condition

Abstract

Enhancement in the production of enzyme by utilizing different strains of microbe is one of the main prospects in biotechnology. In the present work, ethyl methane sulfonate (EMF) was selected as the chemical mutagen for inducing mutagenesis in fungi. It is a cheap method to induce random mutation as compared to other methods of recombinant technologies. Strain improvement was done by incubating the fungal spore suspension at variable concentrations of EMS i.e. 4% (v/v) and 10% (v/v) for the time period of 60, 90, and 120 min respectively. The set of control was treated with distilled water only. The fungal colonies were found to be maximum in control plate as compared to the EMF exposed plates. The number of fungal colonies was reduced as we raised the exposure time of EMF. Specific activity and the lipase activity of wild strain and hyperproducer were evaluated under the submerged (SmF) and solid-state fermentation (SSF). The wild strain denoted the 3.2 U/ml/min of enzymatic activity under SmF and 15.87 U/g/min of activity under SSF. In contrast, the best enzymatic activity was represented by S2St1 at 10% of EMS after the time period of 60 min i.e. 11.7 U/ml/min under SmF and 99.35 U/g/min under SSF after the time period of 72 hrs. Statistical analysis by using one-way ANOVA determined that the value of F calculated was lower than the F tabulated. So, there was a significant relation between the EMS percentage and time of exposure among the mutated strains. In conclusion, this soil fungal strain can be utilized to produce lipase enzyme for numerous industrial applications.