Production of β-galactosidase by Kluyveromyces marxianus MTCC 1388 using whey and effect of four different methods of enzyme extraction on β-galactosidase activity

Whey containing 4.4% (w/v) lactose was inoculated with Kluyveromyces marxianus MTCC 1389 for carrying out studies related to beta-galactosidase production. beta-galactosidase activity was found to be maximum after 30 h and further incubation resulted in decline in activity. The maximum cell biomass of 2.54 mg mL(-1) was observed after 36 h of incubation. Lactose concentration dropped drastically to 0.04% from 4.40% after 36 h of incubation. Out of the four methods tested for extraction of enzyme, SDS - Chlorofom method was found to be best followed by Toluene - Acetone, sonication and homogenization with glass beads in that order. It could be concluded through this study that SDS - Chloroform is cheap and simple method for enzyme extraction from Kluyveromyces cells, which resulted in higher enzyme activity as compared to the activity observed using the remaining extraction methods. The study could also establish that whey could effectively be utilized for beta-galactosidase production thus alleviating water pollution problems caused due to its disposal into the water streams.