Influence of redox potential on metabolism of glucose in mixed cultures of rumen microorganisms.

The rumen inocula taken from cows and sheep were incubated in pH controlled anaerobic batch cultures and the effect of the elevated redox potential (Eh) on metabolism of glucose was examined. In Eh regulated cultures (Eh = +100 mV) the VFA production and production of methane were decreased with a concomitant increase of production of lactate. In these cultures counts of lactilytic bacteria tended to be lower and counts of lactic acid bacteria higher than in cultures with a normal Eh. The elevated Eh also exerted an inhibitory effect on the rumen protozoa. The relevance of these changes to the rumen metabolism is discussed.