Abstract_EANA2025-72

Abstract EANA2025-72

Metagenomic insights into the metabolic diversity of Globally Distributed Hypersaline Environments

Michael C. Macey1, Ben P. Stephens1, Ben Tatton1, Ermias Balcha2, Susanne P. Schwenzer1, Terry J. McGenity3, Hagos Miruts4, Felipe Gomez5, Barbara Cavalazzi6, Karen Olsson-Francis1

1AstrobiologyOU, The Open University, 2Addis Ababa Science and Technology University, 3University of Essex, 4Mekelle University, 5Centro De Astrobiologia, 6University of Bologna

Studying extremophiles enables the characterisation of the boundaries of life on Earth and the identification of metabolic processes that drive biogeochemical cycling under extreme conditions. Here, we present an analysis of the microbiomes from globally distributed hypersaline environments.

We screened published metagenomes from various hypersaline environments, including marine salterns in Spain, hypersaline lakes in Chile and Antarctica, and soda lakes in Egypt and Mongolia [1–5], to examine the presence, diversity, and abundance of shared functional genes that encode enzymes relevant to biogeochemical cycling. The study was further expanded by generating metagenomes from DNA extracted from salt and water samples collected from Lake Karum, an Ethiopian hypersaline lake in the Danakil Depression. A comparative analysis was performed to compare the functional gene profiles across these hypersaline environments.

The microbial community within Lake Karum consisted of Cyanobacteria, Candidate Phyla, and halophilic bacteria and archaea. Screening of the metagenomes identified that phototrophs in hypersaline environments typically possessed the majority of the genes related to carbon dioxide and nitrogen fixation, indicating that they play a major role in driving both the carbon and nitrogen cycles [6-7]. High abundances of genes involved in denitrification, methylamine utilisation, and carbon monoxide oxidation, classified as Halobacterial, were also identified in all the metagenomes, demonstrating that these taxa are crucial in biogeochemical cycling in hypersaline environments [8-9]. Cultivation efforts are required to further define the interactions between the distinct functional clades identified in hypersaline environments.

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