RESUMO
Aspergillus parasiticus microbial type culture collection (MTCC)-2796, a new source of a-galactosidase is an efficient producer of enzyme in basic medium under submerged fermentation conditions. Maximum a-galactosidase production (156.25 Uml-1) was obtained when the basic medium is supplemented with galactose (0.5 percent w/v) and raffinose (0.5 percent w/v) as carbon source and yeast extract as nitrogen source. Enzyme production was also enhanced considerably in the presence of wheat bran (1.0 percent w/v). Enzyme secretion was strongly inhibited by the presence of Hg2+, Cu2+, and Co2+ in the medium and to some extent by Zn2+ and Ni2+, while marginal increase in the enzyme production was observed when Mg2+ and Mn2+ were added in the medium. Among amino acids checked (aparagine, cysteine, glutamine, leucine and proline), glutamine (1 mM) was found to be an enhancer for the enzyme production. The temperature and pH range for the production of enzyme were 25ºC to 35ºC and 6.5 to 7.5, respectively with maximum activity (50 Uml-1) at 30ºC and pH 6.5 under static fermentation condition.