Effects of Temperature and Oxygen on the Growth of Listeria monocytogenes at pH 4.5

Growth effects were studied using tryptose phosphate broth adjusted with hydrochloric acid. The microorganism survived for extended periods at low incubation temperatures (5 and 10°C), and grew at intermediate temperatures (19 and 28°C). Aerobic incubation at 37°C resulted in relatively rapid inactivation of the organism; however, when oxygen was restricted the organism recovered and survived for extended periods. Oxygen restriction enhanced the growth rate at 19°C. Results demonstrated temperature and oxygen availability interacted to influence survival of L. monocytogenes in low pH environment.