Isolamento e caracterização de rizóbios de solos contaminados por manganês para a formação de um banco de estirpes nativas selecionadas

Abstract

The activity of manganese ore has high importance in the world economy, generating raw materials for various industries. However it has high environmental impact with the generation of huge mass of soil polluted by waste. Thus the use of low cost technologies is necessary for rehabilitation of these impacted environments. In this sense revegetation with legumes inoculated with fixing bacteria N has been one of the main strategies used for the rehabilitation of degraded areas by mining. This work is based on the hypothesis that the native rhizobia areas naturally contaminated by Mn are more tolerant to this element andaimed at isolation and morphological characterization of colonies of these bacteria adapted to high Mn concentrations in the soil, using as culture trap the cowpea (Vigna unguiculata(L.) Walp.). It was observed that there is a high diversity of soil rhizobia in researched area, but its nitrogen fixation capacity when associated with the cowpea is apparently reduced by acidity and higher amounts of Mn in the soil. Three isolated, characterized in Yeast Manitol Agar Broth, and the growth morphology of the colonies were observed. The obtained biological material has high genetic value for future experiments involving the use of inoculated legumes species and there foreit will be added to the Bank of rhizobial strains of the Department of Soil Science Soil Microbiology Laboratory of the Center of Agricultural Sciences of the Federal University of Ceará, following a proper coding adoption. It is highly recommended the conduction of further tests for a full certification and efficiency tests with other legume species suitable for planting in areas degraded by mining manganese.