THE ANAEROBIC MONOTRICHOUS BUTYRIC ACID-PRODUCING CURVED ROD-SHAPED BACTERIA OF THE RUMEN

Abstract

A study of many strains of anaerobic curved rods isolated from bovine rumen indicated that 4 fundamentally different groups of bacteria were included. The most numerous group included monotrichous, nonsporeforming, Gram-negative, curved rods fermenting glucose with production of large amounts of butyric acid. This group was placed in the new genus BUTYRIVIBRIO. The type species, B. fibrisolvens nov. spec.,is described on the basis of characteristics of one of the most representative strains. It ferments glucose with the production of CO2, H2, and butyric, formic, and lactic acids. It ferments a large number of carbohydrates including hexoses, pentoses, disaccharides, glycerides and polysaccharides. Members of the genus not placed in the type species differ mainly in the non-fermentation of several of the carbohydrates fermented by the type species. The importance of the genus Butyrivibrio in the rumen is indicated by the fact that strains digest many of the major components of ruminant rations including xylan, cellulose, starch, and protein and appear to be among the most numerous bacteria present in the rumen of cattle and sheep fed a variety of rations.