Amino Acid Metabolism of Penicillin-resistant Staphylococci

Abstract

The amino acid metabolism of 2 organisms made resistant to high levels of penicillin has been compared with that of the penicillin-sensitive parent strain. The penicillin-resistant organisms were similar to the parent strain in their ability to oxidize amino acids. They differed, however, in that they were not able to concentrate free glutamic acid in the internal environment, and in that they were able to synthesize required amino acids from NH3 and glucose. This suggests that the power of internal concentration may be a mechanism evolved to compensate for loss of synthetic ability.