First report on the plasmidome from a high-altitude lake of the Andean Puna

PEREZ, MARIA FLORENCIA; KURTH, DANIEL; FARÍAS, MARÍA EUGENIA; SORIA, MARIANA NOELIA; CASTILLO VILLAMIZAR, GENIS ANDRES; POEHLEIN, ANJA; DANIEL, ROLF; DIB, JULIAN RAFAEL

Frontiers in Microbiology

Frontiers

Lugar: Lausanne; Año: 2020

Mobile genetic elements, including plasmids, drive the evolution of prokaryotic genomesthrough the horizontal transfer of genes allowing genetic exchange between bacteria.Moreover, plasmids carry accessory genes, which encode functions that may offeran advantage to the host. Thus, it is expected that in a certain ecological niche,plasmids are enriched in accessory functions, which are important for their hosts toproliferate in that niche. Puquio de Campo Naranja is a high-altitude lake from theAndean Puna exposed to multiple extreme conditions, including high UV radiation,alkalinity, high concentrations of arsenic, heavy metals, dissolved salts, high thermalamplitude and low O2 pressure. Microorganisms living in this lake need to developefficient mechanisms and strategies to cope under these conditions. The aim of thisstudy was to characterize the plasmidome of microbialites from Puquio de CampoNaranja, and identify potential hosts and encoded functions using a deep-sequencingapproach. The potential ecological impact of the plasmidome, including plasmids fromcultivable and non-cultivable microorganisms, is described for the first time in a lakerepresenting an extreme environment of the Puna. This study showed that the recoveredgenetic information for the plasmidome was novel in comparison to the metagenomederived from the same environment. The study of the total plasmid population allowedthe identification of genetic features typically encoded by plasmids, such as resistanceand virulence factors. The resistance genes comprised resistances to heavy metals,antibiotics and stress factors. These results highlight the key role of plasmids for theirhosts and impact of extrachromosomal elements to thrive in a certain ecological niche.