Comparision of heat resistance of Clostridium spores grown under different condition

초록

The purpose of this study was to study the effect of growth condition on the heat resistance of spores of C. sporogenes. The spores of C. sporogenes were grown in solid and liquid TPGY media under various temperature and pH. Heat resistance was evaluated in phosphate buffer at 121°C. For spores grown in TPGY liquid medium, D-values of the spores were 0.97±0.16 min at 6th weeks, which was very close to that of the spores (D121=0.96±0.22 min) harvested from TPGY agar medium. When compared to culturing spores on solid media, liquid culture was easy to harvest spores and resulted in higher concentration of spores, despite the longer incubation time. The D-values at different pH from 5.5, 6.0, 6.5, 7.0, and 7.8 were 0.92±0.21, 0.87±0.15, 0.87±0.11, 0.52±0.22, and 0.46±0.16 min, respectively. The D-values at different temperature from 8, 20, and 32 °C were 1.01±0.17, 1.35±0.32, and 1.37±0.19, respectively. This result showed that spores grown at low pH and high temperature had higher heat resistance compared to those grown at neutral pH.