Metabolism of pentoses by clostridia. I. Enzymes of ribose dissimilation in extracts of Clostridium perfringens.

Evidence has accumulated indicating that the clostridia ferment glucose by means of a system similar to the Embden-Meyerhof-Parnas (EMP) pathway (Elsden, 1952). In the case of Clostridium perfringens, for instance, most of the enzymes of the EMP pathway have been demonstrated in cell free extracts (Bard and Gunsalus, 1950; Shankar and Bard, 1955). Further evidence for the operation of the EMP pathway in C. perfringens has been provided in the form of studies involving tracer distribution in the products of the fermentation of C14-labeled glucose (Paege et al., 1956). The utilization of pentoses by members of the genus Clostridium has received less attention. Reports in the literature concerning this phase of carbohydrate metabolism in the clostridia have been restricted generally to a listing of the pentoses metabolized and to the products of pentose metabolism. For example, Pr6vot and Taffanel (1942) reported that Clostridium novyi, Clostridium saprotoxicum, and Clostridium hemolyticum metabolized arabinose and xylose, producing ketones, lactic acid, ethanol, and fatty acids of low molecular weight. Bolcato et al. (1952) studied the fermentation of xylose and arabinose by Clostridium acetobutylicum. They isolated and identified as fermentation products triose phosphates and pyruvic acid, and concluded on the basis of this evidence that pentose was fermented by means of a C2-C3 cleavage. It was felt that the metabolism of pentoses by members of the genus Clostridium was worthy