Hitchins A D, Greene R A, Slepecky R A
J Bacteriol. 1972 Apr;110(1):392-401. doi: 10.1128/jb.110.1.392-401.1972.
The size of the spores produced by Bacillus megaterium ATCC 19213 depended upon the nature of the carbon source present in the defined medium in which they were produced. Homogeneous preparations of small (0.38 mum(3)), nearly spherical spores were produced after batch culture in the presence of 2.8 mm citrate, and large (1.17 mum(3)), oblong spores were produced by replacement culture in the presence of 7.35 mm acetate. Large and small spores had approximately the same deoxyribonucleic acid content, density, and heat resistance. Large spores contained about 2.5 times the dipicolinic acid, glucosamine, ribonucleic acid, Mn(2+), and lipid and about 1.5 times the Mg(2+), Fe(2+), Ca(2+), and dry weight of small spores. Large spores were especially enriched in Zn(2+) (4.5-fold). More protein (1.5-fold) was extracted from small spores with 1 n NaOH than from large spores, possibly indicating a difference in the spore coats, but large spores contained about twice the Kjeldahl nitrogen of small spores. A difference in the coats may account for the fact that, unlike small spores, large spores showed improved germination with increased times and temperature of heat shocking. The possibility of determining the location of some of these substances within the spore by comparing the compositional ratios with estimated volumes of specific spore layers is discussed.
巨大芽孢杆菌ATCC 19213产生的孢子大小取决于其产生时所用限定培养基中碳源的性质。在含有2.8 mM柠檬酸盐的条件下进行分批培养后，可产生均一的小（0.38μm³）、近球形的孢子制剂；在含有7.35 mM乙酸盐的条件下进行置换培养，则产生大（1.17μm³）、椭圆形的孢子。大、小孢子的脱氧核糖核酸含量、密度和耐热性大致相同。大孢子中吡啶二羧酸、氨基葡萄糖、核糖核酸、Mn²⁺和脂质的含量约为小孢子的2.5倍，Mg²⁺、Fe²⁺、Ca²⁺和干重约为小孢子的1.5倍。大孢子中Zn²⁺含量尤其丰富（4.5倍）。用1 N NaOH从小孢子中提取的蛋白质（1.5倍）比从大孢子中提取的多，这可能表明孢子壁存在差异，但大孢子的凯氏氮含量约为小孢子的两倍。孢子壁的差异可能解释了这样一个事实，即与小孢子不同，大孢子在热激时间和温度增加时萌发有所改善。文中讨论了通过将组成比例与特定孢子层的估计体积进行比较来确定其中一些物质在孢子内位置的可能性。
