Concomitant production of protease and lipase by Bacillus licheniformis VSG1: production, purification and characterization

ABSTRACT

This study was aimed at producing protease and lipase simultaneously on a common medium by Bacillus licheniformis VSG1, which was isolated from a tannery effluent. The effect of media composition with respect to protein source, lipid source and emulsifier on the production of protease and lipase was analysed. Both those enzymes were produced under optimized conditions like pH, temperature and incubation time. The enzyme mixture comprising of both protease and lipase was purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography to obtain 20-fold pure enzymes. The purified enzyme mixture was characterized to determine the optimum pH and temperature of protease and lipase, the response of the enzymes to inhibitors, additives and solvents. The molecular weight of both the enzymes was determined as 40 kDa on SDS-PAGE. The concomitant production of protease and lipase and the purification of both the enzymes in a single mixture have industrial significance, as many industrial processes use both protease and lipase together.