ATP Pool and Growth Yield in Selenomonas ruminantium

Abstract

SUMMARY The ATP pool in Selenomonas ruminantium growing in continuous culture under carbohydrate-limited conditions was low (averaging 2·3 nmoles/mg dry wt bacteria) and appeared independent of growth rate over the range of optimum growth. The high maximum growth yield (Y gluc62) previously found for another strain of sele-nomonad was confirmed and growth on glucose plus pyruvate gave a calculated value for Y pyr of about 21. A tentative scheme is suggested for production of ATP from electron-transfer reactions which would make the value for Y ATP for high growth-yield rumen anaerobic bacteria nearer to the accepted value of 10 than the values found using previously suggested modes of ATP formation.