RT Journal Article
SR Electronic
T1 Functional analysis of the archaea, bacteria, and viruses from a halite endolithic microbial community
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 029934
DO 10.1101/029934
A1 Alexander Crits-Christoph
A1 Diego R. Gelsinger
A1 Bing Ma
A1 Jacek Wierzchos
A1 Jacques Ravel
A1 Alfonso Davila
A1 M. Cristina Casero
A1 Jocelyne DiRuggiero
YR 2015
UL http://biorxiv.org/content/early/2015/10/26/029934.abstract
AB Halite endoliths in the Atacama Desert represent one of the most extreme microbial ecosystems on Earth. Here we sequenced and characterized a shotgun metagenome from halite nodules collected in Salar Grande, Chile. The community is dominated by archaea and functional analysis attributed most of the autotrophic CO2 fixation to a unique cyanobacterium. The assembled 1.1 Mbp genome of a novel nanohaloarchaeon, Candidatus Nanopetramus SG9, revealed a photoheterotrophic life style and a low median isoelectric point (pI) for all predicted proteins, suggesting a “salt-in” strategy for osmotic balance. Predicted proteins of the algae identified in the community also had pI distributions similar to “salt-in” strategists. The Nanopetramus genome contained a unique CRISPR/Cas system with a spacer that matched a partial viral genome from the metagenome. A combination of reference-independent methods identified over 30 complete or near complete viral or proviral genomes with diverse genome structure, genome size, gene content, and hosts. Putative hosts included Halobacteriaceae, Nanohaloarchaea, and Cyanobacteria. Despite the dependence of the halite community on deliquescence for liquid water availability, this study exposed an ecosystem spanning three phylogenetic domains, containing a large diversity of viruses, and a predominant “salt-in” strategy to balance the high osmotic pressure of the environment.