Humbert R D, DeGuzman A, Fields M L
Appl Microbiol. 1972 Apr;23(4):693-8. doi: 10.1128/am.23.4.693-698.1972.
The heat resistance, fermentation reactions, nutritional requirements, and phage sensitivity of 18 selected morphological variants of Bacillus stearothermophilus NCA 1518 were studied. It was found that when smooth variants mutated to rough colonial morphology, there was no concurrent change in fermentation reactions, nutritional requirements, or heat resistance. The smooth variant, and the rough mutants derived directly from it, presented a uniform pattern of biochemical capabilities which differed from the pattern presented by the rough variants isolated from the same stock culture. This led to the conclusion that the smooth and rough types previously observed in stocks of B. stearothermophilus NCA 1518 either were carried in the stock since the original isolation or represent a very profound and uncommon mutation, or that one of the variants has been introduced into the stock culture from an extraneous source sometime in the past.
对嗜热脂肪芽孢杆菌NCA 1518的18个选定形态变体的耐热性、发酵反应、营养需求和噬菌体敏感性进行了研究。结果发现，当光滑变体突变为粗糙菌落形态时，发酵反应、营养需求或耐热性并未同时发生变化。光滑变体及其直接衍生的粗糙突变体呈现出一致的生化能力模式，这与从同一原种培养物中分离出的粗糙变体所呈现的模式不同。由此得出结论，之前在嗜热脂肪芽孢杆菌NCA 1518原种中观察到的光滑型和粗糙型要么自最初分离以来就存在于原种中，要么代表一种非常深刻且罕见的突变，要么是其中一种变体在过去某个时候从外部来源引入到原种培养物中。
