Studies on the β-galactosidase production were carried out with a bacterial strain isolated from the soil sample near dairy processing plant. The production of extracellular β-galactosidase by Bacillus sp. was optimized in a submerged fermentation. The effect of incubation period, temperature and pH of the medium were optimized. The production of the enzyme was found to be high at the 48th hour after inoculation at 30°C and pH 7. Of the metal ions used, MgCl2 was found to favor the enzyme production. Under optimal conditions, β-galactosidase was allowed to produce by the isolated Bacillus Sp. strain. The enzyme was purified using and the purified β-galactosidase was homogeneous with the molecular weight of 70 kDa as shown by SDS PAGE analysis
