Pm. Dey et al., INDUCTION OF ALPHA-GALACTOSIDASE IN PENICILLIUM-OCHROCHLORON BY GUAR (CYAMOPSIS-TETRAGONOBOLA) GUM, Biotechnology and applied biochemistry, 17, 1993, pp. 361-371
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.