Molecular and phenotypic characterization of endophytic bacteria isolated from sulla nodules.

In the current study, bacterial diversity was investigated in root nodules of Sulla pallida and Sulla capitata. The isolates were analyzed on the basis of their phenotypic and molecular characteristics. The phylogenetic analysis based on 16S rRNA and housekeeping genes (recA and atpD) showed that the isolated bacteria related to Sinorhizobium, Neorhizobium, Phyllobacterium, Arthrobacter, Variovorax and Pseudomonas genera.

Estimating Divergence Times and Substitution Rates in Rhizobia.

Accurate estimation of divergence times of soil bacteria that form nitrogen-fixing associations with most leguminous plants is challenging because of a limited fossil record and complexities associated with molecular clocks and phylogenetic diversity of root nodule bacteria, collectively called rhizobia. To overcome the lack of fossil record in bacteria, divergence times of host legumes were used to calibrate molecular clocks and perform phylogenetic analyses in rhizobia. The 16S rRNA gene and intergenic spacer region remain among the favored molecular markers to reconstruct the timescale of rhizobia.

Molecular phylogenetic analysis of Rhizobium sullae isolated from Algerian Hedysarum flexuosum.

Isolates from root nodules of Hedysarum flexuosum, sampled from north region of Algeria, were analyzed on the basis of their phenotypic and molecular characteristics. They were tested for their tolerance to NaCl, pH, temperatures, antibiotics and heavy metals resistance. Interestingly, the isolate Hf_04N appeared resistant to ZnCl2 (50 μg/mL) and grew at high saline concentration up to 9 %.