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首页> 外文期刊>Journal of bacteriology >Effect of pH on competence development and deoxyribonucleic acid uptake in Streptococcus sanguis (Wicky).
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Effect of pH on competence development and deoxyribonucleic acid uptake in Streptococcus sanguis (Wicky).

机译：pH对血链球菌（Wicky）能力发展和脱氧核糖核酸摄取的影响。

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摘要

Streptococcus sanguis (Wicky) cells, strain WE4, developed little or no competence and failed to autolyze in permissive conditions when treated with competence factor (CF) below PH 7.0. This lack of activity was directly correlated with the inability of the cells to bind or take up CF at pH values of 5.5, 6.0, and 6.5. On the other hand, competent cells bound deoxyribonucleic acid molecules maximally below pH 7.0 and transformed maximally at pH 6.5. Deoxyribonucleic acid was optimally bound to cells in a deoxyribonuclease-resistant form at pH values between 7.0 and 8.5. Concomitant with this binding, undefined acid-soluble DNA fragments appeared in the culture menstrua. CF binding and uptake by cells was not only influenced by low pH but also by low temperature. At 0 C, WE4 cells bound only 4% of the input CF and took up less than 1% into a trypsin-insensitive state compared to cells treated at 37 C. Cells treated with CF at 0 C did not autolyze when transferred to permissive conditions. The results presented in this report extend earlier findings that showed that competence development and autolysis are related to the uptake of CF.
机译：用低于PH 7.0的能力因子（CF）处理时，血链球菌（Wicky）WE4株几乎没有或完全没有能力，在允许的条件下无法自溶。这种活性的缺乏与细胞在pH值为5.5、6.0和6.5时无法结合或吸收CF的能力直接相关。另一方面，感受态细胞最大在pH 7.0以下结合脱氧核糖核酸分子，并在pH 6.5处最大转化。在pH值介于7.0和8.5之间时，脱氧核糖核酸以抗脱氧核糖核酸酶的形式最佳地与细胞结合。伴随这种结合，未定义的酸溶性DNA片段出现在培养的月经中。 CF的结合和细胞摄取不仅受低pH值的影响，而且还受低温的影响。与在37 C下处理的细胞相比，在0 C下，WE4细胞仅结合输入CF的4％，并进入不到胰蛋白酶不敏感状态的比例不到1％。在0 C下用CF处理的细胞转移到允许条件下不会自溶。本报告中提出的结果扩展了先前的发现，这些发现表明能力发展和自溶与CF的吸收有关。

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