The distribution of glutamic acid decarboxylase in the family Enterobacteriaceae examined by a simple chromatographic method

Abstract

SUMMARY: By a simple chromatographic technique with filter-paper disks the distribution of glutamic acid decarboxylase in the family Enterobacteriaceae was surveyed. The decarboxylase occurred irregularly among 230 strains belonging to this family. The test for glutamic acid decarboxylase may prove to be of value in the classification of organisms related to the genus Salmonella, in the classification of paracolon types and in the identification of sub-groups within the genera Escherichia and Aerobacter. We have shown (Proom & Woiwod, 1949) that when bacteria are grown on an acid-hydrolysed casein medium changes may occur in the culture fluids, revealed chromatographically, which are peculiar to certain species or groups of bacteria; and we suggested that they might be of value in bacterial classi-fication. We have now surveyed the distribution of glutamic acid decarboxy-lase (GAD) among strains and species of the family Enterobacteriaceae and have devised a very simple chromatographic technique for demonstrating its presence