Survival and Thermal Inactivation of Coliform Bacteria after the Heat Treatment at 143°F

유우원(乳牛源) 대장균군세균(大腸菌群細菌)의 치사열(致死熱)에 관한 연구

Survival and thermal inactivation after heat treatment at $143^{\circ}F$ were observed among 27 strains of coliform bacteria isolated from dairy cattle. The results obtained were as follows. 1. The obvious differences in heat-sensitivity were observed among the strains tested. 2. No strain was found resistant to the heat treatment of $143^{\circ}F$ for 30 minutes. 3. A marked effect of density of coliform bacteria on the survival after the heat treatment was observed. As the density of coliform bacteria was increased, the rate of survival was increased markedly regardless of the length of heat treatment.