Growth Factors for Selenomonas ruminantium

Abstract

THE effect of volatile fatty acids as growth factors for rumen bacteria is well known, but in most cases so far reported the branched-chain fatty acids, sometimes in combination with straight chain acids, have been found to be most effective. In a recent paper, Bryant and Robinson¹ mentioned that their results showed the importance of acetate in the nutrition of many species of bovine rumen bacteria. However, their strains of S. ruminantium varied in the response to volatile fatty acids, a mixture of such acids other than acetate, propionate and n-butyrate baing stimulatory or essential, while acetate was stimulatory to two strains, but only in the absence of casein hydrolysate. Hobson and Mann² earlier reported that acetate stimulated the growth of isolates of sheep rumen S. ruminantium and some further observations are described in this communication.