Reductive and hydrolytic activities of enteric bacteria on food colours.

Reductive and hydrolytic activities on two food colours namely metanil yellow and indigo carmine by different strains of enteric bacteria were evaluated. Enteric bacteria possessed both reductive and hydrolytic capabilities which depended upon the incubation period and the type of strain. In certain bacterial strains, (Escherichia coli and Vibrio sp.), reductive activity was visible after 3 hr. Other enteric strains showed an increasing activity right from the beginning of incubation. Enterobacter cloacae appeared to be producing maximum reductive capability followed by Enterobacter aerogenes and E. coli. Even enteric bacterial strains demonstrated a good response in obtaining hydrolytic activity of indigo carmine during incubation upto 10 hr, establishing the fact that the gut microflora may cause health problem to consumers.