Schlissel H J, Sword C P
J Bacteriol. 1966 Nov;92(5):1357-63. doi: 10.1128/jb.92.5.1357-1363.1966.
Schlissel, Harvey J. (The University of Kansas, Lawrence), and C. P. Sword. Conditions affecting transformation of a group H streptococcus. J. Bacteriol. 92:1357-1363. 1966.-A defined transforming medium (DTM) containing buffer and 5 to 10 mug per ml of deoxyribonucleic acid was developed to study the physical and chemical requirements for optimal transformation in streptococcal strain SBE. Optimal transformation in DTM occurred at pH 7.5 and 7.0 in 0.07 m sodium phosphate buffer and 0.05 m tris(hydroxymethyl)aminomethane buffer, respectively. In the presence of either a monovalent or a divalent cation, transformation was stimulated maximally by Mn(+2) (10(-3)m) and K(+) (0.05 m). Other cations tested (Na(+), Mg(+2), Ca(+2)) were less stimulatory. A mixture of K(+) and Mn(+2) stimulated transformation to a level higher than either cation alone. Kinetic studies showed that the stimulating effect of cations was greatest during the early part of the transformation reaction and decreased with time. Transformation was inhibited by Cu(+2) (10(-5)m) and Mn(+2) (10(-2)m). Ethylenediaminetetraacetic acid (EDTA) inhibited transformation at 10(-5)m. The inhibition by EDTA could be overcome by Mn(+2) during the early part of the transformation reaction.
施利塞尔，哈维·J.（堪萨斯大学，劳伦斯）和C.P. 索德。影响H群链球菌转化的条件。《细菌学杂志》92:1357 - 1363。1966年。——为了研究链球菌菌株SBE中最佳转化所需的物理和化学条件，开发了一种含有缓冲液和每毫升5至10微克脱氧核糖核酸的限定转化培养基（DTM）。在DTM中，最佳转化分别发生在0.07米磷酸钠缓冲液的pH值为7.5和0.05米三（羟甲基）氨基甲烷缓冲液的pH值为7.0时。在单价或二价阳离子存在的情况下，Mn(+2)（10(-3)米）和K(+)（0.05米）对转化的刺激作用最大。测试的其他阳离子（Na(+)、Mg(+2)、Ca(+2)）的刺激作用较小。K(+)和Mn(+2)的混合物对转化的刺激作用高于单独的任何一种阳离子。动力学研究表明，阳离子的刺激作用在转化反应早期最大，并随时间降低。Cu(+2)（10(-5)米）和Mn(+2)（10(-2)米）抑制转化。乙二胺四乙酸（EDTA）在10(-5)米时抑制转化。在转化反应早期，Mn(+2)可以克服EDTA的抑制作用。
