Sulfur-cycling chemolithoautotrophic microbial community dominates a cold, anoxic, hypersaline Arctic spring

Microbiome

Research

Richard J. Leveille¹  Ianina Altshuler²  Lyle G. Whyte³  Elisse Magnuson³  Nastasia J. Freyria³ 

[1] Department of Earth and Planetary Sciences, McGill University, Montreal, QC, Canada;Geosciences Department, John Abbott College, Ste-Anne-de-Bellevue, QC, Canada;MACE Laboratory, ALPOLE, School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland;Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada;

关键词: Metagenomics;    Metatranscriptomics;    Metagenome-assembled genomes;    Saline spring;    Sulfidic spring;    Cryosphere;   

DOI  :  10.1186/s40168-023-01628-5

 received in 2023-04-12, accepted in 2023-07-19,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundGypsum Hill Spring, located in Nunavut in the Canadian High Arctic, is a rare example of a cold saline spring arising through thick permafrost. It perennially discharges cold (~ 7 °C), hypersaline (7–8% salinity), anoxic (~ 0.04 ppm O2), and highly reducing (~ − 430 mV) brines rich in sulfate (2.2 g.L−1) and sulfide (9.5 ppm), making Gypsum Hill an analog to putative sulfate-rich briny habitats on extraterrestrial bodies such as Mars.ResultsGenome-resolved metagenomics and metatranscriptomics were utilized to describe an active microbial community containing novel metagenome-assembled genomes and dominated by sulfur-cycling Desulfobacterota and Gammaproteobacteria. Sulfate reduction was dominated by hydrogen-oxidizing chemolithoautotrophic Desulfovibrionaceae sp. and was identified in phyla not typically associated with sulfate reduction in novel lineages of Spirochaetota and Bacteroidota. Highly abundant and active sulfur-reducing Desulfuromusa sp. highly transcribed non-coding RNAs associated with transcriptional regulation, showing potential evidence of putative metabolic flexibility in response to substrate availability. Despite low oxygen availability, sulfide oxidation was primarily attributed to aerobic chemolithoautotrophic Halothiobacillaceae. Low abundance and transcription of photoautotrophs indicated sulfur-based chemolithoautotrophy drives primary productivity even during periods of constant illumination.ConclusionsWe identified a rare surficial chemolithoautotrophic, sulfur-cycling microbial community active in a unique anoxic, cold, hypersaline Arctic spring. We detected Mars-relevant metabolisms including hydrogenotrophic sulfate reduction, sulfur reduction, and sulfide oxidation, which indicate the potential for microbial life in analogous S-rich brines on past and present Mars.CDmZk6dAQUX4zKwy7_vWAsVideo Abstract

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

【 图 表 】

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