34-8 Metabolic strategies of bacteria and archaea in response to high temperatures in the Guaymas Basin subsurface (IODP 385)

Session: Recent Advances in the Gulf of California Oblique Rift: Offshore and Onshore Studies // Avances Recientes en el Rift Oblicuo del Golfo de California: Estudios Marinos y Terrestres (Posters)

Poster Booth No.: 8

Presenting Author:

Lei Su

Authors:

Su, Lei¹, Teske, Andreas P², Marshall, Ian PG³, Qi, Wenlong⁴, Liu, Wenqi⁵, Li, Jiangtao⁶

(1) State Key Laboratory of Marine Geology, Tongji University, Shanghai, China, (2) Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, USA, (3) Department of Biology, Aarhus University, Aarhus, Denmark, (4) State Key Laboratory of Marine Geology, Tongji University, China, (5) State Key Laboratory of Marine Geology, Tongji University, China, (6) State Key Laboratory of Marine Geology, Tongji University, China,

Abstract:

The Guaymas Basin, with its steep thermal and geochemical gradients, provides a natural laboratory to study changing microbial diversity and metabolic functions across temperature niches. Here, we analyzed metagenomes from eight deep subsurface sediment samples spanning 4-87 °C, collected during IODP Expedition 385, to investigate microbial community composition, metabolic potentials, and genomic adaptations. We recovered 722 non-redundant metagenome-assembled genomes representing diverse bacterial and archaeal lineages. Microbial communities exhibited clear thermal niche partitioning, with bacterial dominance in cooler sediments and archaeal prevalence at higher temperatures. Comparative genomic analyses revealed temperature-linked functional shifts, including enrichment of thermotolerance genes (reverse gyrase, heat-shock proteins), membrane lipid biosynthesis pathways (GDGT synthesis and ring cyclization), and specialized carbon and sulfur metabolic pathways. Respiratory gene distributions further highlighted niche differentiation in sulfur, nitrogen, and hydrogen cycling. Our results demonstrate how microbial genomes encode adaptations enabling survival and ecosystem functioning across extreme thermal gradients, advancing understanding of biogeochemical processes in dynamic hydrothermal environments.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3, 2026

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