Degradation of xanthine by Penicillium chrysogenum

SUMMARY: Penicillium chrysogenum utilized the purines hypoxanthine, xanthine, uric acid and adenine as sole nitrogen sources but not the methylated purines caffeine and theobromine. Cell-free extracts of this organism contained the enzymes xanthine dehydrogenase, uricase, allantoinase, allantoicase and urease. Uric acid was degraded to allantoic acid by way of allantoin; allantoin was degraded to glyoxylic acid by way of allantoic acid. Xanthine dehydrogenase, uricase, allantoinase and urease were constitutive whereas allantoicase was inducible by xanthine or allantoin.