β-GALACTOSIDASE OF PARACOLOBACTRUM AEROGENOIDES ,

Abstract

The [beta]-galactosidase of P. aerogenoides, a slow fermenter of lactose, is described. P. aerogenoides [beta]-galactosidase appears to be identical with the [beta]-galactosidase of Escherichia coli with respect to its kinetic properties such as substrate affinity, pH optimum, and activation by the Na and K ions; and also with respect to its metabolic stability. , P. aerogenoides [beta]-galactosidase is highly labile to dilution, heat, urea, trypsin, and toluene as compared to the E. coli [beta]-galactosidase. No serological relationship between the P. aerogenoides and E. coli [beta]-galactosidase was detected. The P. aerogenoides [beta]-galactosidase is only slightly inducible.