Warth A D
J Bacteriol. 1980 Jul;143(1):27-34. doi: 10.1128/jb.143.1.27-34.1980.
Inactivation rates for nine enzymes extracted from Bacillus cereus spores were measured at several temperatures, and the temperature at which each enzyme had a half-life of 10 min (inactivation temperature) was determined. Inactivation temperatures ranged from 47 degrees C for glucose 6-phosphate dehydrogenase to 70 degrees C for leucine dehydrogenase, showing that spore enzymes were not unusually heat stable. Enzymes extracted from vegetative cells of B. cereus had heat stabilities similar to the respective enzymes from spores. When spores were heated and the enzymes were subsequently extracted and assayed, inactivation temperatures for enzymes within the spore ranged from 86 degrees C for glucose 6-phosphate dehydrogenase to 96 degrees C for aldolase. The internal environment of the spore raised the inactivation temperature of most enzymes by approximately 38 degrees C. Loss of dipicolinic acid from spores was initially slow compared with enzyme inactivation but increased rapidly with longer heating. Viability loss was faster than loss of most enzyme activities and faster than dipicolinic acid release.
在几个温度下测定了从蜡样芽孢杆菌孢子中提取的9种酶的失活速率，并确定了每种酶半衰期为10分钟时的温度（失活温度）。失活温度范围从6-磷酸葡萄糖脱氢酶的47℃到亮氨酸脱氢酶的70℃，表明孢子酶的热稳定性并不异常。从蜡样芽孢杆菌营养细胞中提取的酶与来自孢子的相应酶具有相似的热稳定性。当孢子被加热，随后提取并测定酶时，孢子内酶的失活温度范围从6-磷酸葡萄糖脱氢酶的86℃到醛缩酶的96℃。孢子的内部环境使大多数酶的失活温度提高了约38℃。与酶失活相比，孢子中吡啶二羧酸的损失最初较慢，但随着加热时间延长而迅速增加。活力丧失比大多数酶活性的丧失更快，也比吡啶二羧酸的释放更快。
