N-carbamoyl-beta-D(+)-glucopyranosylamine metabolism by rumen microbes

Degradation of N-carbamoyl-beta-D(+)-glucopyranosylamine (NCG) by rumen microorganisms in vitro required a viable population as it did not occur if the microbial preparation had been sterilized. Production of CO2 from glucose, or the glucose portion of NCG, was not affected by acetohydroxamic acid (AHA), but urea hydrolysis was inhibited by 79%. With N-[14C]carbamoyl-beta-D(+)-glucopyranosylamine, production of 14CO2 decreased and [14C]urea accumulated when AHA was included in the medium. Cell-free rumen fluid did not degrade NCG. These observations support the hypothesis that the first nitrogenous component formed from the degradation of NCG is urea.