Young «oil site» of the Uzon Caldera as a habitat for unique microbial life

Abstract

Background The Uzon Caldera is one of the places on our planet with unique geological, ecological, and microbiological characteristics. Uzon oil is the youngest on Earth. Uzon oil has unique composition, with low proportion of heavy fractions and relatively high content of saturated hydrocarbons. Microbial communities of the «oil site» have a diverse composition and live at high temperatures (up to 97 °C), significant oscillations of Eh and pH, and high content of sulfur, sulfides, arsenic, antimony, and mercury in water and rocks. Results The study analyzed the composition, structure and unique genetics characteristics of the microbial communities of the oil site, analyzed the metabolic pathways in the communities. Metabolic pathways of hydrocarbon degradation by microorganisms have been found. The study found statistically significant relationships between geochemical parameters, taxonomic composition and the completeness of metabolic pathways. It was demonstrated that geochemical parameters determine the structure and metabolic potential of microbial communities. Conclusions There were statistically significant relationships between geochemical parameters, taxonomic composition, and the completeness of metabolic pathways. It was demonstrated that geochemical parameters define the structure and metabolic potential of microbial communities. Metabolic pathways of hydrocarbon oxidation was found to prevail in the studied communities, which corroborates the hypothesis on abiogenic synthesis of Uzon hydrothermal petroleum.

Local and global chemical shaping of bacterial communities by redox potential

“…Dashed lines represent fits with a slope of less than 0.01 V -1 . Numbers for datasets are (1) Bison Pool, Yellowstone National Park (unlike the other datasets, DNA was extracted from biofilm samples) (Swingley et al, 2012), (2) acidic and (3) circumneutral to alkaline New Zealand hot springs (Power et al, 2018), (4) Dallol Geothermal Area (hypersaline and moderate to extremely acidic water) (Belilla et al, 2019), (5) Copahue Volcano-Río Agrio (Lopez Bedogni et al, 2020;Massello et al, 2020), (6) Southwestern Yunnan (seven samples with pH > 7 and two moderately acidic samples) (Guo et al, 2021), (7) Eastern Tibetan Plateau (Guo et al, 2020), (8) Uzon Caldera (nine samples for acidic water and sediment and one high-pH sample) (Peltek et al, 2020), (9) Southern Tibetan Plateau (Ma et al, 2021), (10) Japan Hydrothermal Sediment (Omae et al, 2019). See Figure S1 for individual sample values.…”

Community- and genome-based evidence for a shaping influence of redox potential on bacterial protein evolution

“…Colors are used to represent sample characteristics (acidic water, circumneutral to alkaline water, and sediment). Numbers for data sets are (1) acidic and (2) circumneutral to alkaline New Zealand hot springs ( 15 ), (3) Eastern Tibetan Plateau ( 36 ), (4) Uzon Caldera (including nine samples for acidic water and sediment and one high-pH sample) ( 37 ), and (5) Southern Tibetan Plateau ( 38 ).…”