Studies on the physiology of Bacillus fastidiosus.

Bacillus fastidiosus was grown in a minimal medium that contained uric acid or allantoin, aerated by vigorous stirring. A constant, optimum pH of 7.4 was maintained by controlled addition of sulfuric acid. Washed cells converted both urate and allantoin into carbon dioxide and ammonia, simultaneously assimilating part of the available carbon and nitrogen. Urate oxidase (formerly called uricase) was present in extracts from urate-grown but not allantoin-grown cells. The formation of urate oxidase was apparently induced by urate. Urea was detected as an intermediate in some but not all of these experiments. However, the high urease activity observed in cell-free extracts may have prevented accumulation of urea in many of the experiments. The presence of glyoxylate carboligase and tartronic semialdehyde reductase activities indicates that the glycerate pathway may be involved in urate and allantoin catabolism in this organism.