An improved all-metal temperature-gradient incubator produces its gradient by means of a bar permanently installed in a near-vertical position with its lower end in a cool constant-temperature water bath and with thermostatically controlled heaters near its top. Bolts hold the incubator in contact with the temperature-gradient bar, and polyurethane foam insulates the entire assemblage during use. Maximal growth temperatures of 34 representative strains of Salmonella were found to be between 43.2 and 46.2 C. In an agar medium with an initial level of 106 cells per milliliter, no strain survived 50 C for 48 hr. S. senftenberg 775W showed no greater heat resistance at or near 48 C than did other species or other S. senftenberg strains. However, it was considerably more resistant than other strains at 55 C.
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机译:改进的全金属温度梯度培养箱通过永久性地安装在接近垂直位置的棒产生其梯度,该棒的下端位于凉爽的恒温水浴中,并且在其顶部附近装有恒温控制的加热器。螺栓将培养箱与温度梯度条保持接触,并且聚氨酯泡沫在使用过程中使整个组件绝缘。发现34个代表性沙门氏菌菌株的最高生长温度在43.2和46.2℃之间。在琼脂培养基中,初始水平为每毫升10 6个sup细胞,在48小时内没有菌株在50℃下存活。 S. senftenberg 775W在48 C或附近的温度下没有显示比其他物种或其他S. senftenberg菌株更高的耐热性。但是,它在55℃的抗性比其他菌株强得多。
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