A Study of Actively Cellulolytic Rod-Shaped Bacteria of the Bovine Rumen

Abstract

Summary Eight strains of anaerobic, Gram-negative, nomnotile, actively ecllulolytic, rod-shaped bacteria found in large nmnbers in rumcn contents were selected for study on the basis of variation in morphology, pigment production, and isolation from different animals fed different rations. Of many carbon sources tested, only glucose, cellobiose, cellulose, and pectin were fermented by all strains. Large amounts of succinic and acetic acid alnl smaller amounts of formic acid were produced, and carbon dioxide was taken up, in the fermentation of celhfiose. It was concluded that all strains belonged to one species, Bacteriodes succinogeues Hungate. Studies on the growth requirements showed that bicarbonate is required and suggested that rmnen fluid contains an unknown heat, acid, and alkali-stable factor that is not a common B vitamin, amino acid, peptide, purine, pyrimidinc, or mineral and was not detected in several materials commonly used to grow nutritionally fastidious bacteria or in extracts from alfalfa meal or bovine feces.