RT Journal Article SR Electronic(1) A1 Stephenson, Michael P. A1 Jackson, Frank A. A1 Dawes, Edwin A.YR 1978 T1 Further Observations on Carbohydrate Metabolism and its Regulation in Azotobacter beijerinckii JF Microbiology, VO 109 IS 1 SP 89 OP 96 DO https://doi.org/10.1099/00221287-109-1-89 PB Microbiology Society, SN 1465-2080, AB Certain enzymes of glucose catabolism in Azotobacter beijerinckii were studied and their activities in steady-state chemostat cultures were measured under various nutrient limitations. 2-Keto-3-deoxy-6-phosphogluconate aldolase was separated from 6-phosphogluconate dehydratase by affinity chromatography and the previously observed inhibition of the Entner-Doudoroff enzymes by tricarboxylic acids and ATP was attributed to chelation of Mn2+ and Mg2+ which activate the dehydratase. Glucose-6-phosphate dehydrogenase was unaffected by phosphoenolpyruvate while fructose-1,6-bisphosphate aldolase was activated by Co2+, K+ or NH4 + ions. Transketolase, transaldolase and triosephosphate isomerase were present but previous reports of 6-phosphogluconate dehydrogenase activity were shown to be artefacts. The findings confirm the major role of the Entner-Doudoroff pathway in glucose catabolism in A. beijerinckii. Pyruvate dehydrogenase, a key enzyme for carbon entry to the tricarboxylic acid cycle and to poly-β-hydroxybutyrate synthesis, was inhibited by acetyl-coenzyme A and NADH., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-109-1-89