Steinkraus K H, Tashiro H
Appl Microbiol. 1967 Mar;15(2):325-33. doi: 10.1128/am.15.2.325-333.1967.
A comparative study was made of all available milky-disease species and strains that have been isolated around the world from beetle larvae (family Scarabaeidae). Included in the study were Bacillus popilliae Dutky, B. lentimorbus Dutky, and B. lentimorbus var. maryland from the United States; B. euloomarahae Beard and B. lentimorbus var. australis Beard from Australia; B. fribourgensis Wille from Switzerland; and New Zealand milky disease (Dumbleton). The organisms were classified into three groups: (i) those containing parasporal bodies, including B. popilliae Dutky, B. fribourgensis Wille, and New Zealand milky disease (Dumbleton); (ii) those without a visible parasporal body and with spore morphology similar to B. lentimorbus Dutky, including B. lentimorbus var. australis Beard; and (iii) those with very tiny spores and no parasporal body, including B. euloomarahae Beard and B. lentimorbus var. maryland. All available milky-disease species and strains were cultivated in vitro on Brain Heart Infusion Agar plates. However, the most fastidious organisms-B. euloomarahae and B. lentimorbus var. maryland-could not be grown until they were passed through a life cycle in larvae of a large scarabaeid beetle infesting rotting wood. Then they remained stable for only one or two subcultures. All the milky-disease organisms produced larger cells in vitro than they did in vivo. The pattern of sugar fermentations was similar for all milky-disease species. It appears that there is a very low percentage of strains of B. popilliae, B. lentimorbus, and the other milky-disease organisms that have the inherent genetic makeup to permit them to sporulate on artificial media, if conditions are favorable. Among these conditions are a sufficiently high cell population and a reduced oxygen tension. Spores produced in vitro may have a low virulence via the normal ingestion pathway, even though they show apparent virulence when injected directly into the hemocoel.
对世界各地从甲虫幼虫（金龟子科）中分离出的所有可用乳状病物种和菌株进行了比较研究。该研究包括来自美国的日本金龟子芽孢杆菌（Bacillus popilliae Dutky）、缓病芽孢杆菌（B. lentimorbus Dutky）和马里兰缓病芽孢杆菌变种（B. lentimorbus var. maryland）；来自澳大利亚的欧洛马腊哈芽孢杆菌（B. euloomarahae Beard）和澳大利亚缓病芽孢杆菌变种（B. lentimorbus var. australis Beard）；来自瑞士的弗里堡芽孢杆菌（B. fribourgensis Wille）；以及新西兰乳状病（邓布尔顿）。这些微生物被分为三组：（i）含有伴胞晶体的，包括日本金龟子芽孢杆菌、弗里堡芽孢杆菌和新西兰乳状病（邓布尔顿）；（ii）没有可见伴胞晶体且孢子形态与缓病芽孢杆菌相似的，包括澳大利亚缓病芽孢杆菌变种；（iii）孢子非常小且没有伴胞晶体的，包括欧洛马腊哈芽孢杆菌和马里兰缓病芽孢杆菌变种。所有可用的乳状病物种和菌株都在脑心浸液琼脂平板上进行体外培养。然而，最难培养的微生物——欧洛马腊哈芽孢杆菌和马里兰缓病芽孢杆菌变种——在通过侵染腐烂木材的大型金龟子科甲虫幼虫的生命周期之前无法生长。然后它们仅在一两次传代培养中保持稳定。所有乳状病微生物在体外产生的细胞比在体内产生的细胞大。所有乳状病物种的糖发酵模式相似。似乎日本金龟子芽孢杆菌、缓病芽孢杆菌和其他乳状病微生物中，只有极低比例的菌株具有内在的基因组成，在条件有利时能够在人工培养基上形成孢子。这些条件包括足够高的细胞数量和降低的氧张力。体外产生的孢子通过正常摄食途径的毒力可能较低，尽管直接注射到血腔中时它们表现出明显的毒力。
