INDUCTION OF ALPHA-GALACTOSIDASE IN PENICILLIUM-OCHROCHLORON BY GUAR (CYAMOPSIS-TETRAGONOBOLA) GUM

High yields of extracellular alpha-galactosidase from fungal cultures were obtained by inducing enzyme production with guar gum (a galactoma nnan obtained from the seeds of Cyamopsis tetragonobola) as the sole c arbon source. An alpha-galactosidase was isolated from the culture med ium of Penicillium ochrochloron culture and purified 867-fold by CM-ce llulose and Sephacryl S-200 column chromatography to apparent homogene ity. Gel-filtration data revealed an M(r) of 57 500, which was in clos e agreement with SDS/PAGE M(r) estimation, for a single band, of 60200 . The alpha-galactosidase activity is strictly dependent upon the pH a nd temperature of the incubation medium, being maximal at pH 4.5 and 5 5-degrees-C respectively. This enzyme from P. ochrochloron was isolate d and purified, devoid of beta-mannanase activity, which cleaves the m ain beta-mannan backbone of galactomannans and greatly diminishes its gel-promoting capacity. The properties of purified guar-gum-induced al pha-galactosidase activity in P. ochrochloron culture were evaluated i n order to ascribe a possible application for alpha-galactosidase in t he controlled generation of an improved guar-gum-based gel promoter.