Catabolic Reactions of Mixed Suspensions of Bovine Rumen Bacteria

Abstract

Several carbon compounds known to be involved in metabolic processes were tested with mixed suspensions of bovine rumen bacteria under anaerobic conditions. Standard microrespiration apparatus and a macrodis-similation technic were used. Substrates used were cellobiose, maltose, glucose, xylose, pyruvate, lactate, oxalacetate, succinate, fumarate, ma late, formate, acetate, propionate, butyrate, and beta-hydroxybutyrate. Detns. were made for volatile fatty acids, keto acids, lactic acid, gases, and polysaccharide synthesis. Cellobiose and glucose, but not maltose, were attacked with CO2 as the sole gaseous end-product. Acetate, propionate, butyrate, and hydroxybutyrate were not dissimilated with gaseous products but formate was decomposed to H2 and CO2. When carbohydrates were the substrate a mixture of acetic, propionic and higher fatty acids was found. Acetic acid was the chief end-product except with succinate and maltose. Fatty acids, if metabolized, yielded only acetic acid.