Concomitant Production, Partial Purification and Characterization of a Serine Protease and a Proteolysis-Resistant Metallolipase from Bacillus pumilus SG2

Abstract

Our objective was to investigate the concomitant production of protease and lipase by a bacterial strain. A promising bacterial strain was isolated from a food-processing industrial effl uent, which can produce both protease and lipase. The isolate was characterized by sequencing the16S rRNA gene. The PCR amplifi ed gene was subjected to analysis by BLAST to ascertain the genetic relatedness of the isolate, Bacillus pumilus SG2. The enzymes were produced and subjected to purifi cation by ammonium sulfate precipitation and dialysis followed by gel fi ltration chromatography; twelve-fold purity was obtained. The lipase produced was found to be proteolysis-resistant. The partially purifi ed enzymes were characterized for their optimum pH value, temperature, response to inhibitors, surfactants and oxidants. The relative molecular weights of protease and lipase were determined as 28 kDa and 40 kDa, respectively, by zymogram studies.