Deep Subsurface Hypersaline Environment as a Source of Novel Species of Halophilic Sulfur-Oxidizing Bacteria

Abstract

The sulfur cycle participates significantly in life evolution. Some facultatively autotrophic microorganisms are able to thrive in extreme environments with limited nutrient availability where they specialize in obtaining energy by oxidation of reduced sulfur compounds. In our experiments focused on the characterization of halophilic bacteria from a former salt mine in Solivar (Presov, Slovakia), a high diversity of cultivable bacteria was observed. Based on ARDRA (Amplified Ribosomal DNA Restriction Analysis), at least six groups of strains were identified with four of them showing similarity levels of 16S rRNA gene sequences lower than 98.5% when compared against the GenBank rRNA/ITS database. Heterotrophic sulfur oxidizers represented ~34% of strains and were dominated by Halomonas and Marinobacter genera. Autotrophic sulfur oxidizers represented ~66% and were dominated by Guyparkeria and Hydrogenovibrio genera. Overall, our results indicate that the spatially isolated hypersaline deep subsurface habitat in Solivar harbors novel and diverse extremophilic sulfur-oxidizing bacteria.

Cold Sulfur Springs—Neglected Niche for Autotrophic Sulfur-Oxidizing Bacteria

“…Additionally, the microbiota of cold sulfur spring emanating from deep saline aquifers were dominated by unique chemolithoautotrophic sulfur-oxidizing Thiomicrospira -related bacterial species [ 117 , 133 , 134 ]. Similar evidence of the Thiomicrospira -related species was observed in a saline spring that emerged from the deep subsurface in Slovakia [ 127 ]. Interestingly, based on the relatively low 16S rRNA gene sequence similarities, the microbiota were composed of completely novel species of sulfur-oxidizing bacteria.…”

Microbial mats as model to decipher climate change effect on microbial communities through a mesocosm study

“…The WA treatment presented Guyparkeria , Ilumatobacter , and MAT-CR-H6-H10 as bacterial biomarkers ( Figure 4 ). Guyparkeria genus includes autotrophic sulphur oxidizers ( Nosalova et al, 2022 ). Ilumatobacter species are generally found in contaminated places by hydrocarbons ( Peng et al, 2015 ; Papale et al, 2020 ).…”

Thiothrix and Sulfurovum genera dominate bacterial mats in Slovak cold sulfur springs

“…Therefore, to recover more complex information of sulfur spring bacterial diversity two different DNA extraction methods were used. Despite the richness of Slovakia in sulfur mineral waters, there are no reports on the diversity of sulfur springs in this region, except our recent studies [ 43 – 45 ]. Moreover, this is the first study comparing the microbiota of several sulfur springs in Slovakia using a 16 S rRNA gene sequencing.…”