Ng H
Appl Environ Microbiol. 1982 May;43(5):1016-9. doi: 10.1128/aem.43.5.1016-1019.1982.
The effects of various growth conditions on the heat resistance of Arizona bacteria grown in a continuous-culture device (chemostat) were studied. Using either glucose, NH4Cl, NaH2PO4, or MgCl2 as the rate-limiting nutrient, it was found that the heat resistance, in all cases depended on the dilution rate and, hence, growth rate of the culture. Cells grown at high dilution rates were less heat resistant than those grown at low dilution rates. If, however, the dilution rate was maintained at a constant rate, the higher the growth temperature, the more heat resistant were the cells. Also at any given dilution rate, the cells were most heat resistant when grown at a near neutral pH. Most survival curves were biphasic in shape, indicating the presence in the population of two fractions of cells, one fraction being more resistant than the other. The size of the more heat-resistant fraction varied from almost 100% in very slow-growing cultures to practically 0% in cultures grown at a dilution rate of 0.67 h-1.
研究了在连续培养装置（恒化器）中培养的亚利桑那菌在各种生长条件下的耐热性。以葡萄糖、氯化铵、磷酸二氢钠或氯化镁作为限制性营养物质，发现在所有情况下，耐热性均取决于稀释率，因此也取决于培养物的生长速率。在高稀释率下生长的细胞比在低稀释率下生长的细胞耐热性更低。然而，如果稀释率保持恒定，生长温度越高，细胞的耐热性越强。同样，在任何给定的稀释率下，细胞在接近中性pH值时生长时耐热性最强。大多数存活曲线呈双相形状，表明群体中存在两类细胞，其中一类比另一类更具抗性。耐热性更强的细胞比例在生长非常缓慢的培养物中几乎为100%，而在稀释率为0.67 h-1的培养物中实际上为0%。
