Seasonal dynamics of extremely halophilic microbial communities in three Argentinian salterns

GOMARIZ, M; ANTON, J.; SANTOS, F.; LÓPEZ, C.; DI MEGLIO, L.; ALMANSA, C; NERCESSIAN, D.

FEMS MICROBIOLOGY ECOLOGY

Oxford University Press

Lugar: Oxford; Año: 2016 vol. 92

0168-6496

Aseasonal sampling was carried out in three Argentinian salterns: Salitral Negro(SN), Colorada Grande (CG) and Guatraché (G), aimed to analyze abiotic parametersand microbial diversity and dynamics. Microbial assemblages were correlated toenvironmental factors by statistical analyses. Principal-Component-Analysis ofenvironmental data grouped SN and CG, separately from G samples, owing to its higherpH values and sulfate concentration. Differences in microbial assemblages werealso found. Many archaeal sequences belonged to uncultured members of Haloquadratum and Haloquadratum-related genera, with different environmental optima. Notably,nearly half of the archaeal sequences affiliated to the recently described ?Candidatus Haloredividus? (phylum Nanohaloarchaeota),not previously detected in salt-saturated environments. Most bacterial sequencesbelonged to Salinibacterrepresentatives, while sequences affiliated to the recently described genus Spiribacter were also found. Seasonalanalysis showed at least 40% of the microbiota from the three salterns wasprevalent along the year, indicating they are well adapted to environmentalfluctuations. On the other side, a minority of archaeal and bacterial sequenceswere found to be seasonally distributed.Fiveviral morphotypes and also eukaryal predators were detected, suggestingdifferent mechanisms for controlling prokaryotic numbers. Notably, Guatrachéwas the saltern which harbored the highest virus-to-cell ratios reported todate for hypersaline environments.