Lactose hydrolysis by P - galactosidase from a newly isolated bacterial strain Bacillus sp. NV1

Abstract

P-Galactosidase (EC 3.2.1.23) was produced from mesophilic bacterial strain Bacillus sp. NV l from local milk plant. The enzyme was partially purified using ammonium sulphate (20-70%). The optimum temperature of P-galactosidase was 40°C and pH range wa 6-7. The enzyme was quite stable and lost 40% activity in 6 hat 50°C with t112 of 3 hat 55°C. The enzyme was slightly inhibited by Fe3 + and Cu2 + and activated by Na\ Ni\ Ca+ and Zn+, Co2 + with K m of 20.83 mM and V max of204.08 U/ml. The partially purified enzyme hydrolyzed 98% of lactose (5%) within 12 h of incubation thereby making this enzyme useful for various industrial purposes.