Twenty-eight types of lysozyme-sensitive spores among seven Bacillus species representative of thermophiles, mesophiles, and psychrophiles were obtained spanning a 3,000-fold range in moist-heat resistance. The resistance within species was altered by demineralization of the native spores to protonated spores and remineralization of the protonated spores to calcified spores and by thermal adaptation at maximum, optimum, and minimum sporulation temperatures. Protoplast wet densities, and thereby protoplast water contents, were obtained by buoyant density sedimentation in Nycodenz gradients (Nyegaard and Co., Oslo, Norway). Increases in mineralization and thermal adaptation caused reductions in protoplast water content between limits of ca. 57 and 28% (wet weight basis), and thereby correlated with increases in sporal heat resistance. Above and below these limits, however, increases in mineralization and thermal adaptation correlated with increases in sporal resistance independently of unchanged protoplast water contents. All three factors evidently contributed to and were necessary for heat resistance of the spores, but dehydration predominated.
展开▼
机译：获得了代表嗜热菌，嗜温菌和嗜冷菌的七个芽孢杆菌属中的28种溶菌酶敏感孢子，其耐湿热性为3000倍。物种内的抗性通过天然孢子的脱矿质化为质子化的孢子和质子化的孢子再矿化为钙化的孢子以及通过在最大，最佳和最小孢子形成温度下的热适应而改变。通过以Nycodenz梯度（Nyegaard and Co.，奥斯陆，挪威）进行浮力密度沉降获得原生质体的湿密度，从而得到原生质体的水含量。矿化作用和热适应性的增加导致原生质体含水量减少，其范围在约200℃至200℃之间。 57％和28％（以湿重为基准），并因此与耐热性的提高相关。然而，高于和低于这些极限，则矿化和热适应性的增加与sporal抗性的增加相关，而与原生质体水含量不变无关。所有这三个因素显然对孢子的耐热性有贡献，并且是耐热性所必需的，但脱水占主导地位。
展开▼
