Degradation of nucleic acid derivatives by rumen bacteria in vitro

Abstract

1. Purine or pyrimidine bases, nucleosides or nucleotides were incubated, in vitro, with whole rumen contents, or with a cell-free filtrate prepared from rumen contents of calves fed on diets of flaked maize and hay.2. During incubations with whole rumen contents, all derivatives bearing a side amino group were deaminated to varying extents.3. All nucleotides and nucleosides were rapidly degraded to the parent base or its desamino counterpart.4. Evidence suggests that guanosine was degraded to guanine before deamination occurred whereas deamination preceded ribosidic cleavage for adenosine.5. Xanthine, uracil, hypoxanthine and thymine resisted further degradation to varying degrees.6. Little or no breakdown was observed when any derivative was incubated, in vitro, with cell-free preparations.