Diversity and Activity of Sulfate-Reducing Prokaryotes in Kamchatka Hot Springs

Abstract

Microbial communities of the Kamchatka Peninsula terrestrial hot springs were studied using radioisotopic and cultural approaches, as well as by the amplification and sequencing of dsrB and 16S rRNA genes fragments. Radioisotopic experiments with 35S-labeled sulfate showed that microbial communities of the Kamchatka hot springs are actively reducing sulfate. Both the cultivation experiments and the results of dsrB and 16S rRNA genes fragments analyses indicated the presence of microorganisms participating in the reductive part of the sulfur cycle. It was found that sulfate-reducing prokaryotes (SRP) belonging to Desulfobacterota, Nitrospirota and Firmicutes phyla inhabited neutral and slightly acidic hot springs, while bacteria of phylum Thermodesulofobiota preferred moderately acidic hot springs. In high-temperature acidic springs sulfate reduction was mediated by archaea of the phylum Crenarchaeota, chemoorganoheterotrophic representatives of genus Vulcanisaeta being the most probable candidates. The 16S rRNA taxonomic profiling showed that in most of the studied communities SRP was present only as a minor component. Only in one microbial community, the representatives of genus Vulcanisaeta comprised a significant group. Thus, in spite of comparatively low sulfate concentrations in terrestrial hot springs of the Kamchatka, phylogenetically and metabolically diverse groups of sulfate-reducing prokaryotes are operating there coupling carbon and sulfur cycles in these habitats.

Enhancing Rubber Industry Wastewater Treatment through an Integrated AnMBR and A/O MBR System: Performance, Membrane Fouling Analysis, and Microbial Community Evolution

“…Proteobacteria, starting at 19.20% and spiking to 25.54%, point towards diverse metabolic functions, including sulfate reduction and denitrification. Desulfobacterota, ranging from 9.51% to 5.64%, are also key for sulfur cycling, which aligns with observed sulfammox and SDAD processes [60]. In the anoxic reactor, Proteobacteria dominate (33.95% by Day 220) along with Bacteroidota (18.04% by Day 220), suggesting ongoing denitrification processes [33].…”

Denitrification Performance in Packed-Bed Reactors Using Novel Carbon-Sulfur-Based Composite Filters for Treatment of Synthetic Wastewater and Anaerobic Ammonia Oxidation Effluent

“…This shift might have been caused by changes in the amounts of organic carbon sources in the filters. Furthermore, increase in abundance of Desulfobacterota was observed in the R 2 and R 4 , which is known as the sulfate-reducing bacteria ( Frolov et al, 2021 ); meanwhile, the abundance of Campilobacterota in the R 2 and R 4 was also increased, Campilobacterota has been reported as the sulfide-oxidizing bacteria ( Carrier et al, 2020 ), and the increase in its abundance was likely benefiting from the Desulfobacterota in the R 2 and R 4 .…”

Cultivation of Ulva lactuca changes bacterial community structure and abundances of nitrogen cycling functional genes in an IMTA system

“…The dominant families in the sediment were Desulfocapsaceae, Bacillaceae, Flavobacteriaceae, Rhodobacteraceae, and Woeseiaceae, which were similar in composition and differed in the proportion of dominant bacteria in the system-cultured macroalgae. Desulfocapsaceae (Desulfobacterota) participates in the sulphur cycle (Frolov, et al 2021). Many sulphate-reducing bacteria are closely related to biological nitrogen xation (Sisler and ZoBell 1951).…”