Rao A S, Hodgson B
Microbios. 1984;40(161-162):135-44.
We have shown that penicillin effects a five log10 kill of a growing culture of a prototrophic strain of Bacillus brevis ATCC 10068 and less than a one log10 kill of an auxotrophic mutant incubated in the absence of the auxotrophic requirement. In spite of this, when a mixed culture of auxotrophic and prototrophic strains were incubated with penicillin under conditions conducive for selection of auxotrophic strains, such strains were not recovered. During growth in both AGM and PY media, the majority of B. brevis cells exist in clumps. Although there is no obvious correlation between the numbers of cells in clumps and the stage of growth with either of the growth media used, bigger clumps consisting of hundreds of single cells were observed in the AGM medium. In experiments with a mixed population of auxotrophic mutants previously derived from the B. brevis ATCC 10068 it was demonstrated that the aggregation of the cells occurred in either the presence or the absence of their growth requirements. The importance of this phenomenon in the aggregation of cells is discussed in relation to the isolation of auxotrophic mutants of B. brevis ATCC 10068.
我们已经表明，青霉素对短芽孢杆菌ATCC 10068原养型菌株的生长培养物有5个对数10的杀灭作用，而对在缺乏营养缺陷型需求的情况下培养的营养缺陷型突变体的杀灭作用小于1个对数10。尽管如此，当营养缺陷型和原养型菌株的混合培养物在有利于选择营养缺陷型菌株的条件下与青霉素一起培养时，并未回收此类菌株。在AGM和PY培养基中生长期间，大多数短芽孢杆菌细胞以团块形式存在。尽管团块中的细胞数量与所使用的任何一种生长培养基的生长阶段之间没有明显的相关性，但在AGM培养基中观察到了由数百个单细胞组成的更大团块。在用先前从短芽孢杆菌ATCC 10068衍生的营养缺陷型突变体的混合群体进行的实验中，证明细胞聚集在有或没有其生长需求的情况下都会发生。结合短芽孢杆菌ATCC 10068营养缺陷型突变体的分离，讨论了这一现象在细胞聚集中的重要性。
