SCARPINO P V, PRAMER D
Appl Microbiol. 1962 Sep;10(5):436-40. doi: 10.1128/am.10.5.436-440.1962.
The relationship between death of cells of Escherichia coli in artificial sea water and time was established as linear, and statistical tests demonstrated that the most suitable measure of survival was log per cent after 24 hr. Survival of E. coli in water supplemented with cysteine at levels of 0.284 x 10(-6) to 284 x 10(-6)m was increased greatly over that in untreated water. To provide an insight into the mode of action of cysteine, the effect of concentration of various sulfhydryl and disulfide compounds was measured, and the influence of several compounds that lack a functional sulfur group but which are capable of affecting oxidation-reduction potential was determined. Moreover, a number of substances related structurally to cysteine were tested to ascertain their influence on the survival of cells of E. coli in artificial sea water. It appeared that the beneficial effect of cysteine was not due to the sulfhydryl group of the amino acid or to the ability of the compound to influence oxidation-reduction potential. Some sulfhydryl compounds had no favorable effect and, in general, disulfides were more active than the corresponding sulfhydryl compounds. Substances that lack a functional sulfur group but influence oxidation-reduction potential had no significant activity. The beneficial effect of a number of compounds related structurally to cysteine indicates that both an amino and carboxyl group are required for activity. It is suggested that cysteine and other amino acids act to increase survival of cells of E. coli in sea water by a chelation mechanism.
人工海水中大肠杆菌细胞死亡与时间的关系呈线性，统计测试表明，最适宜的存活衡量指标是24小时后的对数百分比。在添加了浓度为0.284×10⁻⁶至284×10⁻⁶m半胱氨酸的水中，大肠杆菌的存活率比未处理的水中大幅提高。为深入了解半胱氨酸的作用方式，测定了各种巯基和二硫化合物浓度的影响，并确定了几种缺乏功能性硫基团但能影响氧化还原电位的化合物的影响。此外，测试了一些在结构上与半胱氨酸相关的物质，以确定它们对人工海水中大肠杆菌细胞存活的影响。结果表明，半胱氨酸的有益作用并非归因于该氨基酸的巯基或该化合物影响氧化还原电位的能力。一些巯基化合物没有有利作用，总体而言，二硫化物比相应的巯基化合物更具活性。缺乏功能性硫基团但影响氧化还原电位的物质没有显著活性。一些在结构上与半胱氨酸相关的化合物的有益作用表明，活性需要氨基和羧基两者。有人提出，半胱氨酸和其他氨基酸通过螯合机制来提高海水中大肠杆菌细胞的存活率。
