FERMENTATION OF GLUCOSE AND XYLOSE IN RUMINAL STRAINS OF BUTYRIVIBRIO-FIBRISOLVENS

Metabolism of glucose and xylose and parameters of growth were investi gated in strains of Butyrivibrio fibrisolvens ATCC 19171 and CE 51. In the strain ATCC 19171, the composition of fermentation end-products w as the same in cultures supplied with glucose and xylose. The strain C E 51 produced more volatile fatty acids and less lactate from xylose t han from glucose. Cells of this strain grown on xylose possessed phosp hoketolase activity (EC 4.1.2.9). In both strains the production of ce ll dry matter and growth rate were higher in cultures supplied with gl ucose. In xylose-grown cultures butyrivibrios tended to convert more s ubstrate carbon into metabolites and less into cellular material than in cultures grown on glucose.