Metagenomic Analysis of Bottom Sediments of the Karst Meromictic Lake Black Kichier Revealed Abundant Unculturable Thermoplasmatota

• Published in: Microbiology (New York) Vol. 93; no. 2; pp. 128 - 133
• Main Authors: Kadnikov, V. V., Savvichev, A. S., Rusanov, I. I., Beletskii, A. V., Pimenov, N. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-04-2024; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Carbon cycle; Life Sciences; Medical Microbiology; Meromictic lakes; Metagenomics; Microbiology; Microbiomes; Organic matter; Sediments; Short Communications; Thermoplasmata; 16S rRNA; metagenome; microbial communities; bottom sediments; meromictic Lakes
• ISSN: 0026-2617; 1608-3237
• DOI: 10.1134/S0026261723604359

Investigations into the microbial community of bottom sediments in the karst Lake Black Kichier were conducted. These sediments exhibited elevated levels of sulfide, dissolved methane, and organic matter. Direct radiotracer experiments revealed substantial rates of microbial processes involved in the decomposition of organic matter. Uncultivated archaea belonging to the phylum
Thermoplasmatota
were identified within the microbial community. Metagenomic analysis unveiled representatives from five orders:
Methanomassiliicoccales
,
Thermoprofundales
(formerly known as Marine Benthic Group D and DHVEG-1), DTX01, SG8-5, and
Candidatus
Gimiplasmatales (formerly UBA10834). These archaea were previously believed to occur exclusively in deep marine sediments characterized by extreme organic matter scarcity. This discovery reshapes our understanding of the role played by
Thermoplasmatota
archaea, spanning five orders, in the degradation segment of the carbon cycle.