Production and partial purification of β-galactosidase enzyme from probiotic Bacillus subtilis SK09

139-144In the present study, lactose hydrolyzing enzyme β-galactosidase was produced from a novel probiotic Bacillus subtilis SK09 and it was compared with commercially obtained, B. subtilis MTCC 2413. The probiotic Bacilli was initially screened for its ability to hydrolyze the X-gal followed by production of blue colonies. The production medium was formulated using varied nutrients including carbon, nitrogen, mineral salts and amino acid sources. The crude enzyme with an activity of 76.2 U/ml was achieved from our novel strain B. subtilis SK09, and subjected for partial purification by solvent precipitation, dialysis and ion exchange chromatography using DEAE cellulose (DEAE-C) column. Partially purified β-galactosidase enzyme showed 11.6 folds increase in specific activity of 137.02 U/ml. This partially purified enzyme was further characterized and it was observed that it is homogeneous in nature, with molecular weight of 43 kDa. When compared, the β-galactosidase activity of our novel strain was found five times higher than that of commercially obtained strain (27.6 U/ml). Hence, this characteristic of B. subtilis SK09 of increase enzymatic activity can make it a promising candidate for various industrial as well as biotechnological applications