Pseudomonas aeruginosa mutants resistant to urea inhibition of growth on acetanilide.
Pseudomonas aeruginosa AI 3 was able to grow in medium containing acetanilide (N-phenylacetamide) as a carbon source when NH4+ was the nitrogen source but not when urea was the nitrogen source. AIU mutants isolated from strain AI 3 grew on either medium. Urease levels in bacteria grown in the presence of urea were 10-fold lower when NH4+ or acetanilide was also in the medium, but there were no apparent differences in urease or its synthesis between strain AI 3 and mutant AIU 1N. The first metabolic step in the acetanilide utlization is catalyzed by an amidase. Amidases in several AIU strains showed altered physiochemical properties. Urea inhibited amidase in a time-dependent reaction, but the rates of the inhibitory reaction with amidases from the AIU mutants were slower than with AI 3 amidase. The purified amidase from AIU 1N showed a marked difference in its pH/activity profile from that obtained with purified AI 3 amidase. These observations indicate that the ability of strain AIU 1N and the other mutants to grow on acetanilide/urea medium is associated with a mutation in the amidase structural gene; this was confirmed for strain AIU 1N by transduction.
D000083:Acetanilides / Q000378:metabolism*; D000581:Amidohydrolases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D000645:Ammonium Sulfate / Q000378:metabolism; D005796:Genes; D007773:Lactates / Q000378:metabolism; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014161:Transduction, Genetic; D014508:Urea / Q000378:metabolism / Q000494:pharmacology*; D014510:Urease / Q000096:biosynthesis / Q000378:metabolism
D000083:Acetanilides; D007773:Lactates; D014508:Urea; D000581:Amidohydrolases; D014510:Urease; D000645:Ammonium Sulfate