ABC transport is inactivated by the PTS(Ntr) under potassium limitation in Rhizobium leguminosarum 3841.

PTS(Ntr) is a regulatory phosphotransferase system in many bacteria. Mutation of the PTS(Ntr) enzymes causes pleiotropic growth phenotypes, dry colony morphology and a posttranslational inactivation of ABC transporters in Rhizobium leguminosarum 3841. The PTS(Ntr) proteins EI(Ntr) and 2 copies of EIIA(Ntr) have been described previously.

Soil factors exhibit greater influence than bacterial inoculation on alfalfa growth and nitrogen fixation.

In order to study the effects of soil factors and bacterial inoculation on alfalfa (Medicago sativa), plants were inoculated with Ensifer meliloti L33 and Azospirillum brasilense Sp7 in pot experiments using two different soils separately as well as in a mixture. One soil was contaminated with chemical waste products; the other was an arable soil. Soil factors, including the availability of macro- and micronutrients as well as carbon and nitrogen contents, were found to exhibit a much greater influence on the growth of alfalfa than any of the inoculations.

Direct amplification of rhizobial nodC sequences from soil total DNA and comparison to nodC diversity of root nodule isolates.

A group-specific primer set was developed using nodC as a target gene for the amplification of rhizobial sequence diversity from nodule isolates and total soil DNA preparations. The primer set was tested on 209 nodule isolates, recovered from six different trap plant species which were grown in two soil samples collected from a chickpea and a wheat field site in India. We also amplified and cloned PCR products from total DNA isolated from the same soil samples.

The C-terminal receiver domain of the Rhizobium leguminosarum bv. viciae FixL protein is required for free-living microaerobic induction of the fnrN promoter.

The Rhizobium leguminosarum bv. viciae VF39 FixL protein belongs to a distinct group of hybrid regulatory sensor proteins that bear a covalently linked C-terminal receiver domain. FixL has an unorthodox histidine kinase domain, which is shared with many other hybrid regulators.

Regulation of L-alanine dehydrogenase in Rhizobium leguminosarum bv. viciae and its role in pea nodules.

Alanine dehydrogenase (AldA) is the principal enzyme with which pea bacteroids synthesize alanine de novo. In free-living culture, AldA activity is induced by carboxylic acids (succinate, malate, and pyruvate), although the best inducer is alanine. Measurement of the intracellular concentration of alanine showed that AldA contributes to net alanine synthesis in laboratory cultures.

The Rhizobium leguminosarum bv. viciae VF39 gamma-aminobutyrate (GABA) aminotransferase gene (gabT) is induced by GABA and highly expressed in bacteroids.

A Rhizobium leguminosarum bv. viciae VF39 gene (gabT) encoding a gamma-aminobutyrate (GABA) aminotransferase was identified, cloned and characterized. This gene is thought to be involved in GABA metabolism via the GABA shunt pathway, a theoretical bypass of the 2-oxoglutarate dehydrogenase complex.

The Rhizobium leguminosarum bv. viciae glnD gene, encoding a uridylyltransferase/uridylyl-removing enzyme, is expressed in the root nodule but is not essential for nitrogen fixation.

A Rhizobium leguminosarum bv. viciae VF39 gene (glnD) encoding the uridylyltransferase/uridylyl-removing enzyme, which constitutes the sensory component of the nitrogen regulation (ntr) system, was identified, cloned and characterized. The deduced amino acid sequence contains the conserved active site motif of the nucleotidyltransferase superfamily and is highly homologous to the glnD gene products of other bacterial species.