Droffner M L, Yamamoto N
J Gen Microbiol. 1985 Oct;131(10):2789-94. doi: 10.1099/00221287-131-10-2789.
Thermophilic mutants were isolated from mesophilic Bacillus subtilis and Bacillus pumilus by plating large numbers of cells and incubating them for several days at a temperature about 10 degrees C above the upper growth temperature limit for the parent mesophiles. Under these conditions we found thermophilic mutant strains that were able to grow at temperatures between 50 degrees C and 70 degrees C at a frequency of less than 10(-10). The persistence of auxotrophic and antibiotic resistance markers in the thermophilic mutants confirmed their mesophilic origin. Transformation of genetic markers between thermophilic mutants and mesophilic parents was demonstrated at frequencies of 10(-3) to 10(-2) for single markers and about 10(-7) for two unlinked markers. With the same procedure we were able to transfer the thermophilic trait from the mutant strains of Bacillus to the mesophilic parental strains at a frequency of about 10(-7), suggesting that the thermophilic trait is a phenotypic consequence of mutations in two unlinked genes.
通过接种大量细胞并在比亲代嗜温菌的最高生长温度上限高约10摄氏度的温度下孵育数天，从嗜温性枯草芽孢杆菌和短小芽孢杆菌中分离出嗜热突变体。在这些条件下，我们发现了能够在50摄氏度至70摄氏度之间生长的嗜热突变菌株，其频率低于10^(-10)。营养缺陷型和抗生素抗性标记在嗜热突变体中的持久性证实了它们的嗜温起源。嗜热突变体与嗜温亲代之间遗传标记的转化在单标记情况下频率为10^(-3)至10^(-2)，两个不连锁标记情况下频率约为10^(-7)。通过相同的程序，我们能够以约10^(-7)的频率将嗜热性状从芽孢杆菌突变菌株转移到嗜温亲代菌株，这表明嗜热性状是两个不连锁基因中突变的表型结果。
