Microbiological Studies ofColi-aerogenesBacteria

The cell-free extracts of coli-aerogenes produced glyoxylate and succinate in addition to pyruvate and α-ketoglutarate when incubation was carried out with a citrate-medium. The fresh cell-extracts possessed a very poor ability to produce α-ketoglutarate from citrate, but the addition of coenzyme II (TPN) to the reaction mixtures brought about an increase in the yield of α-ketoglutarate. The degradation of citrate by the intact (washed), dried and ground cells of the bacteria also resulted in an accumulation of glyoxylate in the external medium in which semicarbazide was present. It was suggested that the concentration of coenzyme II within the bacterial cells was relatively low, so that coenzyme II-dependent isocitric dehydrogenase was not operative at such a high rate enough to effect the complete removal of citrate. The bacterial cells revealed a high potency of producing α-ketoglutarate from pyruvate or succinate under aerobic conditions. It was indicated that the major breakdown of citrate by the cel...