Soil microbiome in different environments and protected areas, with Atlantic Forest and Cerrado remnants: a metagenomic approach

Abstract

Prospection, selection, and enzymatic characterization of superoxide dismutase and catalase in metagenomic libraries from different soils: The intense industrial progress observed currently generates large amounts of pollutants that are harmful to the environment. These residues cause irreversible impacts to the sites where it is introduced and it is common the use of organisms as biomarkers for these polluted sites. The relationship between the enzymatic activity and the effects caused by the stressor in living systems causes the production of reactive oxygen species (ROS) such as superoxide ion (O2-), hydrogen peroxide (H2O2), hydroxyl radical (OH-) and single free oxygen (O1). These compounds can cause cell death if not neutralized and, therefore, the aerobic organisms have developed a defense mechanism against oxidative stress and also the synthesis of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione S-transferase (GST). These biomolecules are used in industrial processes and presented the advantage of high specificity to the substrate in relation to chemicals, significantly reducing the production of products in undesirable reaction and purification steps, and presents the possibility of immobilization and recovery of these enzymes for new uses in the process, not requiring high temperatures and pressures in different operations. In general, these biocatalysts are obtained at different scales (laboratory, pilot or industrial) making the use of recombinant DNA technology from the expression of homologous or heterologous genes of biotechnological interest. The oxido-reductases such as SOD and CAT are used in the same way that the hydrolytic enzymes, however, have enormous potential for use as the trend in increasing market share, as in the medical, analytical and scientific, clinical diagnostics, food industry in the formulation of cosmetics, and in bioremediation process of effluents containing phenolic compounds and aromatic amines. In this context, the tool called metagenomics has been widely used to obtain enzymes of biotechnological interest, mainly because this approach will allow access to genes from uncultivable microorganisms, since the analysis involving the study of microbial diversity showed that we know just 1% presented in biosphere. (AU)