Microbiomes of the high-altitude Lake Pastos Grandes in Bolivia. Microbial and functional diversity found in microbiomes of the high-altitude Lake Pastos Grandes in Bolivia

Lake Pastos Grandes has an average altitude of 4400 m.a.s.l. and is mainly composed of salt flats, which are sporadically submerged in some regions during the wet season. The lake has been exposed to high UV radiation as well. We provide results on the first metagenomic studies on this lake. Physicochemical analyses were also performed. Samples were taken from a water pond of Lake Pastos Grandes, some of its river inflows, and a soil sample obtained from the salt flat. Bacteria and eukaryotes had the highest relative abundances across the sampling points, although archaea and cyanobacteria showed appreciable presence in one of the water incomes and the salt flat. The relative abundances of the bacterial orders Burkholderiales and Psudomonadales were noteworthy in the water samples, whereas the archaea belonging to the Halobacteriales and Cyanobacteria from subsection III had particularly high abundances in the salt flat. The eukaryotes Crustacea and Diatomea also exhibited high abundances in the water samples. The principal component analysis further revealed that high concentrations of metal ions such as magnesium, potassium, sodium, and lithium were more likely to be found in one of the rivers. Moreover, genes related to cell biosynthesis (glnA, gs K00266, asnB), nitronate monooxygenase (nmo), and dissimilatory (nirD) or assimilatory (nasA) nitrate reduction had the highest relative abundances in the N-cycle constructed for this lake. Additionally, rifamycin resistance genes (rpoB2, rpoB) and genes related to efflux pumps had the uppermost relative abundances in all sampling points.