[Production of phage-resistant mutants of E. coli, producers of penicillin acylase].
Full resistance to the virulent phage C1 in E. coli N68 is usually accompanied by decreased capacity for penicillinacylase production. For rapid selection of phage resistant mutants possessing penicillinacylase activity comparable with that of the initial bacteria a method was proposed. The method provided comparison of the penicillinacylase activity of the bacterial colonies grown on solid media with addition of phenylacetic acid as the enzyme inductor. A great number of mutants forming colonies on the solid medium in the presence of phage C1 was compared with the use of the above method and a mutant of E. coli N68-PR-I resistant to the phage with penicillinacylase activity equal to 68 per cent of that of the bacteria of the wild type was selected. Mutant N68-R-5 with increased resistance to phage CI was selected among the mutants of E. coli N68 resistant to rifampicin. The penicillinacylase activity of this mutant was not less than of E. coli N68. Phage CI can lyse the cells of strain N68-R-5. Still these bacteria possess a markedly decreased capacity for the phage reproduction.
D000581:Amidohydrolases / Q000096:biosynthesis*; D001736:Biureas / Q000494:pharmacology; D003090:Coliphages / Q000302:isolation & purification*; D003470:Culture Media; D004352:Drug Resistance, Microbial; D004794:Enzyme Repression; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D009154:Mutation / Q000187:drug effects; D009607:Nitrosourea Compounds / Q000494:pharmacology; D010399:Penicillin Amidase / Q000096:biosynthesis*; D012293:Rifampin / Q000037:antagonists & inhibitors; D012641:Selection, Genetic
D001736:Biureas; D003470:Culture Media; D009607:Nitrosourea Compounds; D000581:Amidohydrolases; D010399:Penicillin Amidase; D012293:Rifampin
Poluchenie fagoustoĭchivykh mutantov E. coli-produtsentov penitsillinatsiliazy