Analysis of bacterial phospholipid markers and plant monosaccharides during forage degradation by Ruminococcus flavefaciens and Fibrobacter succinogenes in co-culture.

Marker components of the phospholipids of Ruminococcus flavefaciens and Fibrobacter succinogenes were identified for studies on the degradation of forage by these bacteria growing in mixed culture. The principal fatty acid methyl esters and dimethyl acetals detected varied between strains and were influenced by the addition of a mixture of higher volatile fatty acids and vitamins to the medium, but these effects were small compared to the differences between the species. When two strains of R. flavefaciens were grown on a mixture of clover and ryegrass, and on barley straw in the presence or absence of two strains of F. succinogenes, the solubilization of plant material tended to be lowered by the presence of F. succinogenes. R. flavefaciens was the predominant bacterium among colonies recovered from roll tubes, and the phospholipids were primarily those of R. flavefaciens. Analysis of the culture supernatant liquids showed that F. succinogenes produced greater amounts of free and bound xylose from both clover and straw than did R. flavefaciens. With both forages, cultures containing the two species produced more soluble free arabinose, and less soluble-bound arabinose, than either species grown alone.