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Retama raetam (RR) and R. sphaerocarpa (RS) are shrubs growing in Algeria desert areas, where are commonly used as healing remedies because of their antiseptic, antipyretic and anti-diarrheal properties. Phytochemical studies have shown that these species are very rich in flavonoids (isoflavones) and alkaloids (quinolizidine and bipiperidyl). The aim of this study was to compare the chemical composition of both Retama species by GC/MS and LC/MS and to determinate their antimicrobial activity of two Retama species growing naturally in Algeria. Ten alkaloids and seven flavonoids were identified in cladodes of RR and RS. The quantitative analysis showed that the most abundant flavonoid of both the aqueous extract from RR and RS was the isoflavone genistein (610.0±2.8 and 408.0±14.1 mg/100 g respectively), whereas sparteine was the predominant alkaloid in RR and retamine in RS. The antibacterial activity of Retama extracts against standard strains was performed by minimum inhibitory concentration (MIC), and by the disc diffusion method (expressed by inhibition zone, IZ). Both Retama species showed the best activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), being RS aqueous extract more active than RR aqueous extract, with MIC 125 µg/mL and bactericidal activity against both strains.

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Fifty-one rhizobial strains isolated from root nodules of Cytisus villosus growing in Northeastern Algeria were characterized by genomic and phenotypic analyses. Isolates were grouped into sixteen different patterns by PCR-RAPD. The phylogenetic status of one representative isolate from each pattern was examined by multilocus sequence analyses of four housekeeping genes (16S rRNA, glnII, recA, and atpD) and one symbiotic gene (nodC). Analysis of 16S rRNA gene sequences showed that all the isolates belonged to the genus Bradyrhizobium. Phylogenetic analyses based on individual or concatenated genes glnII, recA, and atpD indicated that strains cluster in three distinct groups. Ten out of the sixteen strains grouped together with Bradyrhizobium japonicum, while a second group of four clustered with Bradyrhizobium canariense. The third group, represented by isolates CTS8 and CTS57, differed significantly from all other bradyrhizobia known to nodulate members of the Genisteae tribe. In contrast with core genes, sequences of the nodC symbiotic gene from all the examined strains form a homogeneous group within the genistearum symbiovar of Bradyrhizobium. All strains tested nodulated Lupinus angustifolius, Lupinus luteus, and Spartium junceum but not Glycine max. From these results, it is concluded that C. villosus CTS8 and CTS57 strains represent a new lineage within the Bradyrhizobium genus.