Diversity and Efficiency of Rhizobia from a Revegetated Area and Hotspot-Phytophysiognomies Affected by Iron Mining as Indicators of Rehabilitation and Biotechnological Potential.

This study aimed to evaluate the resilience of phytophysiognomies under influence of iron mining by assessing the occurrence, diversity, and symbiotic efficiency of native communities of nitrogen-fixing bacteria that nodulate leguminous plants (rhizobia) in soils of an area revegetated with grass after iron mining activities and in the phytophysiognomies in adjacent areas (Canga, Atlantic Forest, Cerrado, and Eucalyptus-planted forest). Experiments for capturing rhizobia through two species of promiscuous plants, siratro (Macroptilium atropurpureum) and cowpea (Vigna unguiculata), were conducted in a greenhouse. The rhizobial strains isolated were characterized phenotypically, genetically (16S rRNA sequencing and BOX-PCR fingerprinting), and regard symbiotic efficiency of biological nitrogen fixation (BNF) compared to mineral nitrogen and reference strains.