Coal mining rejects can raise the concentration of heavy metals and impede the growth of plants in these areas. One strategy for restoring these environments is the association of microorganisms with the rhizosphere, which can help promote plant growth, as well as decreasing the toxicity of heavy metals. The objective of this study was to isolate and identify endospore-forming rhizobacteria (EFR) in areas affected by coal-mining waste, in a deposit in the municipal district of Capivari de Baixo, Santa Catarina (Brazil) and to evaluate the plant growth-promoting potential of bacteria in the revegetation of ecosystems destroyed by mining, based on tests for resistance to metallic elements and siderophore production. Of the EFR identified, those of the genus Bacillus were most frequent, and distinct bacterial groups were observed in the two study areas. The strains from the area of pyrite rejects were most resistant to the metals Ni and Cu. Ten strains of the genus Bacillus, Paenibacillus and Aneurinibacillus, besides resisting a higher number of the heavy metals tested, also produced siderophores and their plant growth-promoting potential in areas contaminated with heavy metals was therefore considered most promising.
Bacillus; heavy metals; siderophores
