PROLINE TRANSPORT BY PSEUDOMONAS AERUGINOSA

Characteristics of the proline transport system were investigated in Pseudomonas aeruginosa. This transport system was found to obey saturation kinetics. From amino acid uptake and pool exchange studies the transport system was amino acid specific and specific for the l-isomer. This uptake system was also responsible for the entry of the proline analogues, thiazolidine-4-carboxylic acid, 3.4-dehydroproline, and azetidine-2-carboxylic acid. A mutant which specifically does not accumulate [14C]-proline was isolated and characterized. Proline transport, the ability to degrade the amino acid, and the ability to concentrate proline were induced by growth in the presence of this amino acid. The ability to transport aliphatic or aromatic amino acids was reduced by growth in the presence of proline. The induction of the proline permease was reduced in the presence of glucose. Proline and not a degradation product of proline metabolism was found to be the inducer of this transport system. The accumulation of proline was shown to be N3-sensitive whereas the transport was unaffected. © 1969.