SYNERGISTIC KILLING EFFECT OF GLYCINE AND PENICILLIN, AND RAPID METHODS FOR MUTANT ISOLATION IN PSEUDOMONAS

[摘要] The addition of 3% of glycine and 10units/ml of penicillin G to a culture of Pseudomonas resulted in a rapid death of the bacterium. More than 95% of viable cells were killed within 30min of incubation. Cell wall synthesis, as determined by amino acid incorporation, was inhibited by glycine plus penicillin. It was also noted that penicillin in high concentrations induced some kind of unbalanced growth. Ethylenediaminetetraacetate in a concentration of 1×10-4M had little or no effect on intact cells or cells treated with penicillin but lysed the cells which were treated with glycine and penicillin. The combined action of these chemicals was successfully utilized for the rapid screening of temperature-sensitive mutants from ultraviolet-irradiated cells.N-Nitroso-N-methylurethane was found to be an extremely efficient mutagen for the isolation of temperature-sensitive mutants. The frequency of mutation was so high that mutants can be isolated without any screening procedure.

[学科分类] 微生物学和免疫学