Production of beta-galactosidase from Kluyveromyces fragilis grown on whey.

Optimum conditions for beta-galactosidase production by K. fragilis were studied. Enzyme production has a maximum after 8-12 h of incubation. Composition of whey (from different sources) did not affect enzyme production. Different heart treatments also had no effect. Whey reconstituted to 8-12% total solids and adjusted to pH 4.0 afforded maximum enzyme production. Whereas inorganic nitrogen sources (specially ammonium salts) only slightly stimulated enzyme production, organic nitrogen sources (specially partially digested proteins) provided a nearly four-fold increase in enzyme production. Yeast extract and beef extract and industrial by-products like corn-steep liquor significantly stimulated enzyme production. Manganese and magnesium salts had a very little stimulation effect.