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 galactomannan obtained from the seeds of Cyamopsis tetragonobola) as the sole carbon source. An alpha-galactosidase was isolated from the culture medium of Penicillium ochrochloron culture and purified 867-fold by CM-cellulose and Sephacryl S-200 column chromatography to apparent homogeneity. Gel-filtration data revealed an M(r) of 57,500, which was in close agreement with SDS/PAGE M(r) estimation, for a single band, of 60,200. The alpha-galactosidase activity is strictly dependent upon the pH and temperature of the incubation medium, being maximal at pH 4.5 and 55 degrees C respectively. This enzyme from P. ochrochloron was isolated and purified, devoid of beta-mannanase activity, which cleaves the main beta-mannan backbone of galactomannans and greatly diminishes its gel-promoting capacity. The properties of purified guar-gum-induced alpha-galactosidase activity in P. ochrochloron culture were evaluated in order to ascribe a possible application for alpha-galactosidase in the controlled generation of an improved guar-gum-based gel promoter.
Department of Biochemistry, Royal Holloway College, University of London, Egham, Surrey, U.K.
P M
PM
Dey
S
S
Patel
M D
MD
Brownleader
D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003470:Culture Media; D004790:Enzyme Induction / Q000187:drug effects; D005685:Galactans / Q000494:pharmacology*; D005690:Galactose / Q000031:analogs & derivatives; D008351:Mannans / Q000378:metabolism / Q000494:pharmacology*; D010407:Penicillium / Q000201:enzymology*; D053149:Plant Gums; D013379:Substrate Specificity; D000519:alpha-Galactosidase / Q000096:biosynthesis* / Q000187:drug effects / Q000302:isolation & purification
D003470:Culture Media; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; C012990:galactomannan; C007894:guar gum; D000519:alpha-Galactosidase; D005690:Galactose