BACTERIAL SPORE HEAT-RESISTANCE CORRELATED WITH WATER-CONTENT, WET DENSITY, AND PROTOPLAST SPOROPLAST VOLUME RATIO
BACTERIAL SPORE HEAT-RESISTANCE CORRELATED WITH WATER-CONTENT, WET DENSITY, AND PROTOPLAST SPOROPLAST VOLUME RATIO
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DOI：
10.1128/jb.150.2.870-877.1982
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发表时间：
1982-01-01
影响因子：
3.2
通讯作者：
GERHARDT, P
中科院分区：
文献类型：
--
作者：
BEAMAN, TC;GREENAMYRE, JT;GERHARDT, P
选择了种间和种内的五种类型的休眠芽孢杆菌孢子，其代表了600倍的耐热性范围，测定为D100 [100%死亡时间]值。每种类型的整个孢子和隔离珠被的湿和干密度以及固体和水含量直接从材料的克质量测定，并对间隙水进行校正。原生质体（由内周细胞质膜界定的结构）和孢子体（由外周皮层膜界定的结构）所占据的体积之间的比率是根据对中等薄切片孢子的电子显微照片进行的测量来计算的。在各种孢子类型中，耐热性的指数增加与湿密度直接相关，与含水量和原生质体/孢子体体积比成反比。总之，这些结果支持了一个假设，即耐热性的程度完全或部分地基于休眠孢子中原生质体的脱水和减少的程度，而不涉及达到这种状态的生理机制。
Five types of dormant Bacillus spores, between and within species, were selected representing a 600-fold range in moist-heat resistance determined as a D100 [100% death time] value. The wet and dry density and the solids and water content of the entire spore and isolated integument of each type were determined directly from gram masses of material, with correction for interstitial water. The ratio between the volume ocupied by the protoplast (the structures bounded by the inner pericytoplasm membrane) and the volume occupied by the sporoplast (the structures bounded by the outer pericortex membrane) was calculated from measurements made on electron micrographs of medially thin-sectioned spores. Among the various spore types, an exponential increase in the heat resistance correlated directly with the wet density and inversely with the water content and with the protoplast/sporoplast volume ratio. Altogether the results supported a hypothesis that the extent of heat resistance is based in whole or in part of the extent of dehydration and diminution of the protoplast in the dormant spore, without implications about physiological mechanisms for attaining this state.