L-Proline nutrition and catabolism in Staphylococcus saprophyticus.
Staphylococcus saprophyticus strains ATCC 15305, ATCC 35552, and ATCC 49907 were found to require L-proline but not L-arginine for growth in a defined culture medium. All three strains could utilize L-ornithine as a proline source and contained L-ornithine aminotransferase and Δ(1)-pyrroline-5-carboxylate reductase activities; strains ATCC 35552 and ATCC 49907 could use L-arginine as a proline source and had L-arginase activity. The proline requirement also could be met by L-prolinamide, L-proline methyl ester, and the dipeptides L-alanyl-L-proline and L-leucyl-L-proline. The bacteria exhibited L-proline degradative activity as measured by the formation of Δ(1)-pyrroline-5-carboxylate. The specific activity of proline degradation was not affected by addition of L-proline or NaCl but was highest in strain ATCC 49907 after growth in Mueller-Hinton broth. A membrane fraction from this strain had L-proline dehydrogenase activity as detected both by reaction of Δ(1)-pyrroline-5-carboxylate with 2-aminobenzaldehyde (0.79 nmol min(-1) mg(-1)) and by the proline-dependent reduction of p-iodonitrotetrazolium (20.1 nmol min(-1) mg(-1)). A soluble fraction from this strain had Δ(1)-pyrroline-5-carboxylate dehydrogenase activity (88.8 nmol min(-1) mg(-1)) as determined by the NAD(+)-dependent oxidation of DL-Δ(1)-pyrroline-5-carboxylate. Addition of L-proline to several culture media did not increase the growth rate or final yield of bacteria but did stimulate growth during osmotic stress. When grown with L: -ornithine as the proline source, S. saprophyticus was most susceptible to the proline analogues L-azetidine-2-carboylate, 3,4-dehydro-DL-proline, DL-thiazolidine-2-carboxylate, and L-thiazolidine-4-carboxylate. These results indicate that proline uptake and metabolism may be a potential target of antimicrobial therapy for this organism.
Division of Mathematical and Natural Sciences, MC 2352, Arizona State University at the West Campus, P.O. Box 37100, Phoenix, AZ 85069-7100, USA. charles.deutch@asu.edu
Charles E
CE
Deutch
D001120:Arginine / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D009952:Ornithine / Q000378:metabolism; D009953:Ornithine-Oxo-Acid Transaminase; D011392:Proline / Q000378:metabolism; D011394:Proline Oxidase; D011758:Pyrroles / Q000378:metabolism; D011762:Pyrroline Carboxylate Reductases; D057790:Staphylococcus saprophyticus / Q000378:metabolism*
D003470:Culture Media; D011758:Pyrroles; C015485:delta-1-pyrroline-5-carboxylate; D001120:Arginine; D011392:Proline; D009952:Ornithine; D011762:Pyrroline Carboxylate Reductases; D011394:Proline Oxidase; D009953:Ornithine-Oxo-Acid Transaminase