Salas J A, Guijarro J A, Hardisson C
J Bacteriol. 1983 Sep;155(3):1316-23. doi: 10.1128/jb.155.3.1316-1323.1983.
The metal ion content of spores of five Streptomyces species was studied. A general feature of this study was the finding of a very high calcium content (1.1 to 2.1% of the dry weight). Accumulation of calcium occurred preferentially during the sporulation process. Spore calcium was located in the integument fraction, and more than 95% of the calcium was removed from intact spores by ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. Several divalent cations (Mg2+, Mn2+, Zn2+, and Fe2+) which induced darkening of spores and loss of heat resistance also caused the release of calcium from spores. In addition, darkening of spores was blocked by metabolic inhibitors, whereas calcium excretion was not affected. Two different categories of events in the initiation of germination may be differentiated; first, calcium release from spores which is not energy dependent and is a consequence of triggering of germination by some divalent cations, and second, some other events including loss of heat resistance, loss of spore refractility, and a decrease in absorbance, with at least one energy-dependent step.
对五种链霉菌属孢子的金属离子含量进行了研究。该研究的一个普遍特征是发现钙含量非常高（占干重的1.1%至2.1%）。钙的积累优先发生在孢子形成过程中。孢子钙位于被膜部分，超过95%的钙可通过乙二醇双（β-氨基乙醚）-N,N-四乙酸从完整孢子中去除。几种二价阳离子（Mg2+、Mn2+、Zn2+和Fe2+）可导致孢子变黑和耐热性丧失，同时也会使孢子中的钙释放出来。此外，代谢抑制剂可阻止孢子变黑，但不影响钙的排泄。萌发起始过程中可区分出两类不同的事件；第一，孢子释放钙，这不依赖能量，是某些二价阳离子触发萌发的结果；第二，一些其他事件，包括耐热性丧失、孢子折光性丧失和吸光度降低，其中至少有一个步骤依赖能量。
