title: Enzymes of the Poly-beta-Hydroxybutyrate and Citric Acid Cycles of Rhizobium japonicum Bacteroids.
abstract: The activities of several enzymes of the citric acid and poly-beta-hydroxybutyrate cycles were measured in Rhizobium japonicum 3I1B-143 bacteroids which had been isolated from soybean nodules by sucrose gradient centrifugation. During the period of developing nitrogenase activity, the specific activity of fumarase, hydroxybutyrate dehydrogenase, beta-ketothiolase, and pyruvate dehydrogenase complex increased whereas acetoacetate-succinyl-CoA transferase and isocitrate dehydrogenase decreased. Malate dehydrogenase activity remained constant. The amount of available acetyl-CoA, based on pyruvate dehydrogenase activity, should be sufficient to support both metabolic cycles concurrently. The temporal relationship between nitrogenase activity and poly-beta-hydroxybutyrate accumulation has been reexamined.
authors: Department of Biochemistry and Interdisciplinary Plant Biochemistry-Physiology Group, University of Missouri-Columbia, Columbia, Missouri 65211.
authors: D B
authors: DB
authors: Karr
authors: J K
authors: JK
authors: Waters
authors: F
authors: F
authors: Suzuki
authors: D W
authors: DW
authors: Emerich