The Effect of Growth and Urea Concentration on Ammonia Production by a Urea-hydrolysing Mycoplasma (Ureaplasma urealyticum) Masover, Gerald K. and Catlin, John and Hayflick, Leonard,, 98, 587-593 (1977), doi = https://doi.org/10.1099/00221287-98-2-587, publicationName = Microbiology Society, issn = 1350-0872, abstract= Summary: The rate of accumulation of ammonium ion in cultures of Ureaplasma urealyti-cum was independent of the growth rate and of the initial urea concentration above 0·025% in the medium, although the quantity of ammonium ion accumulating did depend on the initial urea concentration. Ammonium ions accumulated at a similar rate in U. urealyticum cultures of both rapidly and slowly growing organisms. Viable but non-growing ureaplasmas also produced ammonia in complete medium at a lower temperature than usual (25°C) or in an inadequate growth medium at 37°C. The rate of ammonium ion accumulation in a dying culture depended on the number of viable organisms present; this is relevant to diagnostic methods for ureaplasmas which depend on detecting ammonia colorimetrically., language=, type=