Rapid synthesis and metabolism of glutamate in N/sub 2/-fixing bacteroids. [Bradyrhizobium japonicum]
Symbiotic nodule bacteroids are thought to support N/sub 2/ fixation mainly by metabolizing dicarboxylic acids to CO/sub 2/, generating reductant and ATP required by nitrogenase. Bradyrhizobium japonicum bacteroids were isolated anaerobically and incubated at 2% O/sub 2/ with /sup 14/C-labeled succinate, malate, glutamate, or aspartate. /sup 14/CO/sub 2/ was collected, and the bacteroid contents separated into neutral, organic acid, and amino acid fractions. The respiration of substrates, relative to their uptake, was malate > glutamate > succinate > aspartate. Analysis of the fractions revealed that will all substrates the radioactivity was found mostly in the amino acid fraction. The labeling of the neutral fraction was negligible and only a small amount of label was found in the organic acid fraction indicating a small pool size. TLC of the amino acid fraction showed the label to be principally in glutamate. Glutamate contained 67, 80, 97, and 88% of the /sup 14/C in the amino acid fraction in bacteroids fed with succinate, malate, glutamate and aspartate, respectively. The data suggest that glutamate may play an important role in the bacteroid function.
- Research Organization:
- Ohio State Univ., Wooster
- OSTI ID:
- 6065683
- Report Number(s):
- CONF-8707108-
- Journal Information:
- Plant Physiol., Suppl.; (United States), Journal Name: Plant Physiol., Suppl.; (United States) Vol. 83:4; ISSN PPYSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ASPARTIC ACID
BACTERIA
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHROMATOGRAPHY
DICARBOXYLIC ACIDS
GLUTAMIC ACID
HYDROXY ACIDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MALIC ACID
METABOLISM
MICROORGANISMS
NITROGEN FIXATION
ORGANIC ACIDS
ORGANIC COMPOUNDS
RESPIRATION
SEPARATION PROCESSES
SUCCINIC ACID
THIN-LAYER CHROMATOGRAPHY
TRACER TECHNIQUES