1992 Volume 33 Issue 4 Pages 371-377_1
The decarboxylation of gallate by cell-free extracts of Streptococcus faecalis and Klebsiella pneumoniae isolated from the feces of rats was studied.
Gallate decarboxylase in K. pneumoniae seemed to be identical with the constitutive enzyme in K. aerogenes (EC 4.1.1.59). On the other hand, it was found that enzyme in S faecalis was inducible by gallate in both growing and resting cells, and the induction was inhibited by chloramphenicol. The enzyme was partially purified by (NH4)2SO4 fractionation from the extracts of S. faecalis grown with gallate. This enzyme catalyzed the decarboxylation of gallate and 3, 4-dihydroxybenzoic acid (protocatechuic acid). From the differences in substrate specificity, optimum pH and constitutive or inducible character between the enzymes from S. faecalis and other bacteria, the S. faecalis enzyme seems to be novel.
Thus, decarboxylation of gallate by intestinal bacteria was confirmed in experiments at the enzyme level.
