Author(s): Potrikus CJ, Breznak JA
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Abstract Reticulitermes flavipes termites synthesize uric acid via purine-nucleoside phosphorylase (purine-nucleoside: orthophosphate ribosyltransferase, EC 126.96.36.199) and xanthine dehydrogenase (xanthine:NAD(+) oxidoreductase, EC 188.8.131.52), but their tissues lack uricase (urate:oxygen oxidoreductase, EC 184.108.40.206) or any other enzyme that degrades uric acid. Nevertheless, uricolysis occurs in termites, but as an anaerobic process mediated by hindgut bacteria. (14)C-Tracer experiments showed that termites transport uric acid from the site of synthesis and storage (fat body tissue) to the site of degradation (hindgut microbiota) via Malpighian tubules. Moveover, [1,3-(15)N]uric acid dissimilated by gut bacteria in vivo leads to assimilation of (15)N into termite tissues. NH(3), a product of uricolysis, is a potential N source for termites, either directly via glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 220.127.116.11] activity of fat body tissue or indirectly through microbe assimilation. Symbiotic recycling of uric acid N appears to be important to N conservation in these oligonitrotrophic insects.
This article was published in Proc Natl Acad Sci U S A
and referenced in Journal of Biodiversity, Bioprospecting and Development