Growth and Development of Competence in the Group H Streptococci
Growth and Development of Competence in the Group H Streptococci
复制标题
H 族链球菌能力的增长和发展
作者：
J. Lawson;H. Gooder
由H组链球菌，菌株查利斯，能力的生长和发展进行了比较，在合成，半合成，和复杂的媒体方面的文化条件，发病时间和持久性的能力和转化效率。只要在合成系统中严格控制培养条件，常规观察到1%或以上的转化频率。初始pH必须在7.3和7.6之间，并且需要添加新鲜制备的碳酸氢根离子。此外，感受态对培养物的初始搅拌程度敏感。没有证据表明需要“逐步下降”或“不平衡”的增长条件。在复合或半合成培养基中生长的无能力菌株Wicky中，通过添加在合成培养基中生长的有能力期间制备的菌株查利斯的热灭活或过滤培养物，可以激发有能力。
The growth and development of competence by group H streptococci, strain Challis, were compared in synthetic, semisynthetic, and complex media with respect to the cultural conditions required, time of onset and persistence of competence and transformation efficiency. Provided that cultural conditions were strictly controlled in the synthetic system, transformation frequencies of 1% or above were routinely observed. The initial pH must be between 7.3 and 7.6, and the addition of freshly prepared bicarbonate ion was required. Furthermore, competence was sensitive to the degree of initial agitation of the culture. There was no evidence that “step-down” or “unbalanced” growth conditions were required. Competence could be provoked in the incompetent strain Wicky, growing in complex or semisynthetic media, by the addition of heat-killed or filtered cultures of strain Challis prepared during the competent period of growth in synthetic medium.