Identificação de microrganismos aquáticos das regiões de várzea do Arapixuna e do Pixuna do Tapará, através de sequenciamento de nova geração

Abstract

A new approach called metabarcoding for environmental DNA that aims to identify the diversity of taxa and the composition of biodiversity, using universal primers, has been highlighted for its efficiency. Our objective was to identify and compare the aquatic microorganisms in two varzea regions (Pixuna do Tapará and Arapixuna), on the banks of the Amazon River, in the municipality of Santarém-PA, and in different extracts of the water column. The samples were filtered and from the filters the eDNA was extracted, the 16S rRNA gene was amplified through PCR, these products were purified and used for the construction of libraries that were later sequenced using the Next Generation Sequencing technique. Data analyses were performed in R 4.5.0 software. The results showed that there was no statistical difference in biological diversity indices (Richness, Diversity/Shannon and Equitability/Pielou's) among the analyzed regions, when evaluated at the DNA level. The genera identified with abundance greater than 5% were Polynucleobacter, na (which are unidentified genera, or not listed in the reference databases), Hgcl clade and the marine group CL500-29. The families that presented relative abundance values higher than 1% were: Comamonadaceae, Burkholderiaceae, Ilumatobacteraceae, Methylophilaceae, Pedosphaeraceae, and Sporichthyaceae. These families correspond to about 99% of the sequences analyzed. Thus, the eDNA study proved to be efficient for the evaluation of microorganisms present in these várzea areas and, the metabarcoding approach shows promise to assist large-scale biological surveys.