Minimal nitrogen requirements of Corynebacterium renal strains.

Corynebacterium renale strain 10849 was grown in a chemically defined medium containing glucosamine, ammonium sulfate, and 5 amino acids as possible nitrogen sources. Although glucosamine was slightly stimulatory, its omission from the medium had a minimal effect on growth, and washed cells introduced into glucosamine-free medium grew readily through 10 serial transfers, demonstrating that this compound was not required for growth. Individual omissions of isoleucine, valine, methionine, and glutamine resulted in lengthened lag periods and reduced growth rates in initial transfers, but recovery occurred in subsequent serial transfers so that by the 3rd or 4th transfer, growth rates and cell crops were only slightly less than in control cultures in complete medium. Omission of cystine resulted in a permanently low growth rate and reduced cell crop, but this was remedied by substituting various nonnitrogenous compounds containing reduced sulfur. Strain 10849 and 6 additional strains were then serially cultured in a minimal defined medium in which sodium thioglycolate provided reduced sulfur and ammonium sulfate served as sole nitrogen source. Since only ammonium ion was required as the nitrogen source, it could be concluded that C renale, which rapidly hydrolyzes urea, should find an adequate source of nitrogen for growth in the urinary tract of animals.