Diversity and biotechnological potential of microorganisms obtained from Ferruginous caves of the Iron Quadrangle

Cangas represent paleoenvironments that originated millions of years ago, whose geological formation presents high iron concentrations and that shelter hundreds of rare species, underground natural cavities and also provides vital ecological services to society, such as water recharge. Despite this conservation value target, studies in these environments are still scarce. On the other hand, thousands of hectares of cangas have already been irreversibly destroyed to open dozens of iron ore caves especially the Iron Quadrangle (IQ) where miles of mountains have been totally impacted by mining. In an attempt to understand the microbial diversity associated with cavities in this region, a metagenomic analysis of floor and ceiling samples from 7 ferruginous caves and 1 quartzite cave. For this, the total DNA of the samples was extracted and the V4-V5 region of the 16S ribosomal subunit was sequenced using the PGM ™ platform, generating more that six million of reads. Comparative analysis revealed that the ferruginous caves show greater diversity compared to the quartzite cave, and that floor and ceiling samples in the ferruginous caves present wide differentiation in the composition of their microbiota. The results highlight for the first time a mining genetic heritage still unknown in biological studies and show the need to incorporate this area in conservation programs, especially because it is under imminent pressure for anthropic action.