Effect of medium components and metabolic inhibitors on beta-galactosidase production and secretion by Penicillium...

Factors affecting the beta-galactosidase production by Penicillium notatum 1 were studied using fermentation media of different chemical composition. The medium containing lactose, salts, peptone and yeast extract with initial pH 2.5 was selected as the best for enzyme production. Monobasic ammonium phosphate (0.9%) was found to be the best inorganic nitrogen source for lactase production. Various extraction media and metabolic inhibitors were examined for effective releasing of beta-galactosidase from the fungal cells. Using a simple method of mycelium extraction with 0.1 Triton X-100, it was possible to obtain about 4-fold higher amounts of enzyme in the cell free extracts, than those excreted into the post-culture liquid.