Winkler U, Heller K B, Folle B
Arch Microbiol. 1978 Mar;116(3):259-68. doi: 10.1007/BF00417849.
Various mutants (oxas) were isolated from Serratia marcescens SM-6 by selecting for hypersensitivity towards oxacillin. All mutants found are highly pleiotropic and able to yield spontaneous revertants which behave like the wild-type. Mutant W 1421 mostly studied shows the following phenotypic properties not found in the wild-type: (1) The growth is hypersensitive to various antibiotics, detergents and dyes which differ remarkably in their chemical structure and antibacterial action-mechanism, (2) the cells can be easily solubilized by 0;05% Sodium-dodecyl-sulfate, (3) the cells allow the adsorption of the rough-mutant specific Salmonella phage 6SR; (4) strong cellular binding of crystal violet, (5) agglutination of the cells in 0.3% auramin solution and (6) reduced formation of red pigment. Strain W 1421 is assumed to be a lipopolysaccharide-defective mutant. The outer membrane of mutant W 1421 analyzed by Sodium-dodecylsulfate-polyacrylamide gel electrophoresis possesses a single protein less than that of the wild-type. Mutant W 1421 is further characterized by its low exolipase activity; exoprotease and exonuclease activities are as in the wild-type. This specific exoenzyme deficiency can be overcome either by backmutation to oxacillin-resistance or by growing mutant W 1421 in a medium supplemented with certain non-metabolizable polysaccharides, e.g. glycogen or pectin B. Both polysaccharides increase the exolipase activity of the wild-type too.
通过筛选对苯唑西林超敏的菌株，从粘质沙雷氏菌SM-6中分离出了各种突变体（oxas）。所有发现的突变体都具有高度多效性，并且能够产生表现得像野生型的自发回复突变体。研究最多的突变体W 1421表现出以下野生型中未发现的表型特性：（1）对化学结构和抗菌作用机制差异显著的各种抗生素、去污剂和染料生长超敏；（2）细胞可被0.05%的十二烷基硫酸钠轻易溶解；（3）细胞允许粗糙突变体特异性沙门氏菌噬菌体6SR吸附；（4）细胞对结晶紫有强烈的结合作用；（5）细胞在0.3%金胺溶液中发生凝集；（6）红色色素形成减少。菌株W 1421被认为是一种脂多糖缺陷型突变体。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析，突变体W 1421的外膜比野生型少一种蛋白质。突变体W 1421的另一个特征是其外脂肪酶活性较低；外蛋白酶和外核酸酶活性与野生型相同。这种特异性外酶缺陷可以通过回复突变为苯唑西林抗性或通过在补充有某些不可代谢多糖（如糖原或果胶B）的培养基中培养突变体W 1421来克服。这两种多糖也会增加野生型的外脂肪酶活性。
