A BIOCHEMICAL-STUDY OF THE INTERMEDIARY CARBON METABOLISM OF SHEWANELLA-PUTREFACIENS

Cell extracts were used to determine the enzymes involved in the inter mediary carbon metabolism of several strains of Shewanella putrefacien s. Enzymes of the Entner-Doudoroff pathway (6-phosphogluconate dehydra tase and 2-keto-3-deoxy-6-phosphogluconate aldolase) were detected, bu t those of the Embden-Meyerhof-Parnas pathway were not. While several tricarboxylic acid cycle enzymes were present under both aerobic and a naerobic conditions, two key enzymes (2-oxoglutarate dehydrogenase and pyruvate dehydrogenase) were greatly diminished under anaerobic condi tions. Extracts of cells grown anaerobically on formate as the sole so urce of carbon and energy were positive for hydroxypyruvate reductase, the key enzyme of the serine pathway in other methylotrophs, while no hexulose synthase activity was seen.