Intermediate-salinity environments are distributed around the world. Here, we
present a snapshot characterization of two Peruvian thalassohaline environments
at high altitude, Maras and Acos, which provide an excellent opportunity to
increase our understanding of these ecosystems. The main goal of this study was
to assess the structure and functional diversity of the communities of
microorganisms in an intermediate-salinity environment, and we used a
metagenomic shotgun approach for this analysis. These Andean hypersaline systems
exhibited high bacterial diversity and abundance of the phyla Proteobacteria,
Bacteroidetes, Balneolaeota, and Actinobacteria; in contrast, Archaea from the
phyla Euryarchaeota, Thaumarchaeota, and Crenarchaeota were identified in low
abundance. Acos harbored a more diverse prokaryotic community and a higher
number of unique species compared with Maras. In addition, we obtained the draft
genomes of two bacteria, Halomonas elongata and Idiomarina loihiensis, as well
as the viral genomes of Enterobacteria lambda-like phage and Halomonas
elongata-like phage and 27 partial novel viral halophilic genomes. The
functional metagenome annotation showed a high abundance of sequences associated
with detoxification, DNA repair, cell wall and capsule formation, and nucleotide
metabolism; sequences for these functions were overexpressed mainly in bacteria
and also in some archaea and viruses. Thus, their metabolic profiles afford a
decrease in oxidative stress as well as the assimilation of nitrogen, a critical
energy source for survival. Our work represents the first microbial
characterization of a community structure in samples collected from Peruvian
hypersaline systems.
