Cheng J K, Costerton J W, Singh A P, Ingram J M
Antimicrob Agents Chemother. 1973 Mar;3(3):399-406. doi: 10.1128/AAC.3.3.399.
Cells of Pseudomonas aeruginosa suspended in 0.2 M Mg(2+), 20% sucrose, 0.01 M tris(hydroxymethyl)aminomethane, or water partially release lipopolysaccharide. The release of alkaline phosphatase from the periplasmic space and the ability to form spheroplasts on lysozyme treatment is directly related to the lipopolysaccharide released during treatment with 0.2 M Mg(2+), 20% sucrose, or other agents. The synthesis of ribonucleic acid (RNA) by intact cells, magnesium-lysozyme spheroplasts, or 20% sucrose-lysozyme spheroplasts is not sensitive to actinomycin D, whereas RNA synthesis by intact cells or spheroplasts in the presence of ethylene-diaminetetraacetic acid (EDTA) is sensitive to actinomycin D. EDTA alone has an inhibitory effect on RNA synthesis by whole cell, by magnesium-lysozyme spheroplasts, and by 20% sucrose-lysozyme spheroplasts. The experimental data indicate that, although the cell wall is damaged by 0.2 M Mg(2+) or 20% sucrose treatment in the presence of lysozyme, the treated cells or spheroplasts are still resistant to actinomycin D. These results suggest that the cytoplasmic membrane should be considered as the final and determinative barrier to this antibiotic in this organism.
悬浮于0.2 M Mg(2+)、20%蔗糖、0.01 M三（羟甲基）氨基甲烷或水中的铜绿假单胞菌细胞会部分释放脂多糖。碱性磷酸酶从周质空间的释放以及经溶菌酶处理形成原生质球的能力，与在0.2 M Mg(2+)、20%蔗糖或其他试剂处理过程中释放的脂多糖直接相关。完整细胞、镁 - 溶菌酶原生质球或20%蔗糖 - 溶菌酶原生质球的核糖核酸（RNA）合成对放线菌素D不敏感，而在乙二胺四乙酸（EDTA）存在下完整细胞或原生质球的RNA合成对放线菌素D敏感。单独的EDTA对全细胞、镁 - 溶菌酶原生质球和20%蔗糖 - 溶菌酶原生质球的RNA合成具有抑制作用。实验数据表明，尽管在溶菌酶存在下细胞壁因0.2 M Mg(2+)或20%蔗糖处理而受损，但处理后的细胞或原生质球仍对放线菌素D具有抗性。这些结果表明，在该生物体中，细胞质膜应被视为对抗生素的最终决定性屏障。
