Caracterização taxonômica e funcional de organismos e enzimas de interesse biotecnológico em ambientes de mineração

• Ano de defesa: 2016
• Autor(a) principal: Laura Rabelo Leite
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Metagenômica; Biomineração; Diversidade; Bioinformática
• Link de acesso: http://hdl.handle.net/1843/BUOS-ARNJUU

Environments contaminated with heavy metals contain an extremely complex and well adapted community. These microorganisms have enzymes with several biotechnological applications, such as bioremediation and bioleaching, and play an essential role in the biogeochemical cycles. In this context, metagenomics allows to evaluate the genetic potential of cultivable and non-cultivable microorganisms. Here, shotgun and amplicon sequencing (16S rDNA) were used to explore the metabolic and functional diversity of prokaryotes present in two mining environments: a tailings dam and an acid mine drainage. We analyzed water and sediment samples, in the dry (October 2012, July 2014) and wet (April 2013) seasons. The tailings dam sediment and acid mine drainage sediment were characterized as more diverse environments when compared to the tailings dam water. However, the species distribution analysis using ecologic succession models demonstrated that in both groups the species establishment depends on previous environmental conditions. The taxonomic annotation in tailings dam water presented predominance of sequences of the phyla Proteobacteria, Actinobacteria and Cyanobacteria. Acid mine drainage and tailings dam sediment showed higher proportion of sequences related to the phyla Firmicutes, Bacteroidetes, Proteobacteria, Verrucomicrobia, Acidobacteria and Planctomycetes. Functional analysis of these environments highlighted the importance of metabolic pathways related to carbon fixation, nitrogen metabolism, ferrous iron oxidation and sulfur metabolism. In addition, were identified several adaptive mechanisms linked to resistance to heavy metals, tolerance to organic solvents, low pH adaptation and oligotrophy. The present study established a new workflow for metagenomic analysis of shotgun libraries, which was used to build an unprecedented catalog of the biotechnological potential of microorganisms in brazilian copper mines, including genes and metabolic pathways with industrial and environmental interest.