STUDIES ON THE CARBOHYDRATE METABOLISM OF A GRAM-NEGATIVE ANAEROBE ( BACTEROIDES SYMBIOSUS ) USED IN THE CULTURE OF ENTAMOEBA HISTOLYTICA

Abstract

Resting cells of Bacteroides symbiosus have been shown to utilize glucose and several other monosaccharides. The fermentation of the sugars is mediatedby demonstrable kinases except in the case of mannitol. The main end products of metabolism of glucose are CO2, H2, ethanol, and acetic, butyric, succinic,andlactic acids. Changes in the thiol used in the growth media produce different enzyme complements in the cells. Thus, cells grown with cysteine as the thiol are unable to metabolize glucosamine, whereas those grown with thiomalate rapidly degrade the amino sugar. The results of the enzyme assay and the results from experiments with C14 -labelled glucose suggest that glucose is metabolized by resting cells mainly by the Embden-Myerhof pathway.