Extremophilic taxa also predominates in Bacterial community of photovoltaic panels in a tropical region
Photovoltaic panels are elements that can be colonized by a highly diverse microbial diversity, despite life-treating conditions. Although they are worldwide distributed, the microorganisms living on its surfaces have been poorly profiled in tropical regions. Through 16S rRNA high-throughput sequencing and PICRUst metagenome prediction of functional content, photovoltaic panels from two cities of southeast Brazil, Sorocaba and Itatiba, were investigated. Results showed that, despite differences in microbial diversity, the taxonomic profile was very similar for both photovoltaic panels, dominated mainly by Proteobacteria, Bacteroidetes and lower amounts of Cyanobacteria phyla. Moreover, a predominance of Hymenobacter and Methylobacterium-methylorubrum was clearly observed. Analysis of Venn Diagram showed that the microbial common core was composed by Hymenobacter, Deinococcus, Sphingomonas, Methylobacterium-methylorubrum, Craurococcus-caldovatus, Massilia, Noviherbaspirillum and 1174-901-12 (unknown) genera. Predicted functional analysis revealed dominance in metabolisms involved in stress resistance. Among them, specific KEGG Orthology related to radiation, desiccation and pigments were verified, and  associated primarily with the members of common core. Our results suggested that taxonomic and functional profile were consistent with the harsh environment of glass surfaces sun-exposed habitat that photovoltaic panels represents. Furthermore, that might be an ecological succession that selected naturally specific resistant taxa based on adapted microorganisms.