Carbon metabolism in Bradyrhizobium japonicum bacteroids

Carbon metabolism in Bradyrhizobium japonicum bacteroids is reviewed. Additionally, the bacteroid tricarboxylic acid (TCA) cycle and its regulation under oxygen-limited conditions is considered, with emphasis on possible sites of TCA cycle rate-limiting reactions. Furthermore, kve consider other adaptive pathways that may be employed by these organisms while in symbiosis. These pathways include: (1) a poly-fl-hydroxybutyrate shunt, (2) a malate-aspartate shuttle, (3) an a-ketoglutarate-glutamate shunt, (4) a modified dicarboxylic acid cycle, and (5) fermentation pathways leading to lactate, acetaldehyde and ethanol. The effects of oxygen limitation on host carbon metabolism are also considered briefly.