Culture-Independent Survey of Thermophilic Microbial Communities of the North Caucasus

Abstract

The Greater Caucasus is a part of seismically active Alpine–Himalayan orogenic belt and has been a center of significant volcanic activity during the Quaternary period. That led to the formation of the number of hydrothermal habitats, including subterranean thermal aquifers and surface hot springs. However, there are only a limited number of scientific works reporting on the microbial communities of these habitats. Moreover, all these reports concern only studies of specific microbial taxa, carried out using classical cultivation approaches. In this work, we present first culture-independent study of hydrotherms in the Republic of North Ossetia-Alania, located in the southern part of the North Caucasus. Using 16S metabarcoding, we analyzed the composition of the microbial communities of two subterranean thermal aquifers and terrestrial hot springs of the Karmadon valley. Analysis of correlations between the chemical composition of water and the representation of key taxa allowed us to identify the key factors determining the formation of microbial communities. In addition, we were able to identify a significant number of highly abundant deep phylogenetic lineages. Our study represents a first glance on the thermophilic microbial communities of the North Caucasus and may serve as a basis for further microbiological studies of the extreme habitats of this region.

The Genus Iodidimonas: From Its Discovery to Potential Applications

“…Iodidimonas species were also found to be the predominant bacteria in landfill leachate treated in a semi-aerobic aged refuse biofilter [38]. Furthermore, the relative abundances of Iodidimonas and uncultured Iodidimonadaceae-related bacteria were 2% and 7%, respectively, in the Karmadon springs, a geothermal site in North Caucasus [39]. These results suggest that Iodidimonas species are widely distributed and predominate in aerobic, saline, and iodide-rich environments.…”

Effects of Coenzyme Q10 on the Biomarkers (Hydrogen, Methane, SCFA and TMA) and Composition of the Gut Microbiome in Rats

“…Libraries of 16S rRNA V4 hypervariable region were prepared using a two-step PCR strategy as described earlier [ 42 ]. Two library replicates were prepared for each sample.…”

Carbon Emission and Biodiversity of Arctic Soil Microbial Communities of the Novaya Zemlya and Franz Josef Land Archipelagos

“…The amplicon libraries of the hypervariable V4 region of the 16S rRNA gene were prepared using a two-stage PCR strategy with the primers 515F [ 32 ] and Pro-mod-805R [ 33 ]. PCR of every DNA sample was carried out in duplicate; the detailed amplification protocol is described previously [ 34 ]. The libraries were checked with agarose gel and pooled equimolarly.…”