CHARACTERIZATION OF ALPHA-GALACTOSIDASE FROM LACTOBACILLUS-FERMENTUM

alpha-Galactosidase activity was studied in Lactobacillus fermentum st rains. The optimum temperature was found to be 45 degrees C. The enzym e was inactivated at temperatures higher than 55 degrees C, but remain ed active during storage at low temperatures (0, -30 and -70 degrees C ) for 5 months. Enzyme activity was observed within a 5.0-6.5 pH range , while optimum pH was dependent on the particular strain assayed. The addition of Zn2+ to the reaction buffer exerted a slight negative eff ect upon the activity, while Hg2+ and p-chloromercuribenzoate produced a strong inhibition. These results would indicate the presence of -SH groups in the catalytic site of the enzyme.