Metaproteômica comparativa de solos de campos rupestres ferruginosos e de áreas mineradas em recuperação.

Abstract

Despite the economic and social benefits, mining has a strong impact on terrestrial ecosystems, promoting the degradation of soil where this activity is implemented. The regions of Serra dos Carajás - PA and Nova Lima - MG have particularities such as microbial and plant species adapted to the adverse conditions, where ferruginous lateritic soils (canga) and soils associated to sandstones occur. The rehabilitation of mined areas is a mandatory condition for this activity continue to occur in a sustainable manner. Soil metaproteomics is a technique that identifies proteins accumulated by organisms in the environment. Thus, characterization of the protein profile was performed to map, quantify and compare the most abundant biochemical functions in native soils and in areas at different stages of reclamation. From soils collected under these conditions, proteins were extracted, treated and analyzed in liquid chromatography coupled to high resolution mass spectrometry. First, 356 proteins were identified in a sample of forest soil and 147 proteins in a canga soil. In these soils, more functional categories were associated with canga soil, 66 versus 42 in the forest. It was also observed a greater diversity of taxa in the forest, and in the canga species able to tolerate their rigorous environmental condition. Thus, the metaproteomics evidenced molecular responses of microorganisms and plants to a more severe environment and to another richer in nutrients and organic matter. In a second experiment, the metaprotemics was applied in a chronosequence of areas under reclamation (exposed soil, 4, 12, 14 years of reclamation and native areas). The results pointed to the highest amount of proteins identified in the soils with four years of reclamation (336), 12 years (329), 14 years (219) and Native Soils (291), when compared with Expose Soil (40). Although the initial reclamation soil (4 years) has a higher amount of protein, when the abundance of bacterial groups and the functional categorization of proteins are verified, greater similarities are found between advanced reclamation areas and native soils; demonstrating the success of rehabilitation, at least from the soil biochemical point of view. Through metaproteomics we can obtain specific metabolic responses from soil organisms according to the rehabilitation status of the area. Above ali, metaprotemics was able to characterize soil biochemical functions and to discriminate both native and reclamation areas, proving to be a powerful tool for the environmental monitoring of areas of interest.