16S-rRNA analysis for characterization of rhizosphere Zn-resistant bacteria isolated from mining area under semiarid climate

摘要

In order to exploit the ability of the rhizosphere bacterial communities in the remediation of heavy-metal-contaminated soils, we have isolated and identified, by classical techniques, 32 strains associated with Salsola vermiculata and Peganum harmala, two heavy metal tolerant plants grown in a semiarid polluted sandy soils contaminated mainly with Zn. Three Zn-resistant and prevailing strains in the rhizosphere were identified using 16S-rRNA gene sequence analysis. Phylogenetic dendogram based on 16S-rRNA gene sequence indicating that two from the three Zn-resistant isolates are related to pathogenic strains Bacillus anthracis (similarity average of 99.9%) and Entewcoccus durans (similarity average of 99.5%). The third strain is related to Arthrobacter chlorophenolicus (similarity average of 99.4%), a non-pathogenic bacterium.