Physiological and symbiotic diversity of Cupriavidus necator strains isolated from nodules of Leguminosae species

摘要: Biological nitrogen fixation, performed by diazotrophic bacteria, plays an important role in the maintenance of agricultural systems, as it contributes with significant amounts (N) needed for plant growth, totally or partially exempting use industrial N fertilisers. Twenty-five bacterial strains isolated from nodules Leucaena leucocephala and Phaseolus vulgaris trap plants were studied. These formed after inoculation suspensions soil samples collected close to root system Sesbania virgata. In previous studies, these bacteria identified Cupriavidus necator. This study aimed evaluate ability fix N2 free-living state carbon (C) sources; their resistance antibiotics; growth media different pH values salt concentrations symbiotic efficiency L. P. vulgaris. each test, compared C. taiwanensis LMG 19424T. Although a high variability regarding antibiotic resistance, tolerance C sources observed among 25 necator strains, large group behaved similar (20 strains) (22 strains). way Only one studied, UFLA02-69, was not able establish symbiosis its species, LMG19424T UFLA01-672 efficient leucocephala. The sources, grow pHs several antibiotics, may grant saprophytic competence greater competitivity relation native Leguminosae-nodulating populations, suggesting potential inoculant strain selection studies legumes cultivated soils wide range concentrations.