CATALASE, SUPEROXIDE-DISMUTASE AND LISTERIOLYSIN-O PRODUCTION BY LISTERIA-MONOCYTOGENES IN BROTH CONTAINING ACETIC AND HYDROCHLORIC ACIDS

Cells of Listeria monocytogenes 10403S were propagated at 37-degrees-C in media acidified with either acetic or hydrochloric acid to determine the effect on the production of catalase (CA), superoxide dismutase (SOD) and listeriolysin O(LLO). The CA and LLO activities decreased while SOD activity increased as the pH of the growth media was decreased. Comparison of the acids indicated that neither acid caused significant differences in enzyme production except for SOD activity at pH 5.7. These results suggest that growth of L. monocytogenes in acid environments may influence the production of these enzymes, while growth in strong acids versus weak acids may not be significantly different.