Niche Partitioning and Intraspecific Variation of Thaumarchaeota in Deep Ocean Sediments

Area of Science:

• Microbiology
• Deep-sea Ecology
• Genomics

Background:

• Deep-sea sediments host distinct Thaumarchaeota populations.
• Their ecological roles and evolutionary paths remain largely unknown.
• Understanding these microbes is key to deep-ocean ecosystem dynamics.

Purpose of the Study:

• Investigate the ecology and evolutionary adaptations of deep-sea Thaumarchaeota.
• Analyze metagenomes from Mariana Trench sediment cores.
• Identify phylogenetic diversity and genomic variations.

Main Methods:

• Metagenomic sequencing of sediment core samples from the Mariana Trench.
• Analysis of archaeal amoA gene abundance and distribution.
• Phylogenetic classification and comparative genomic analysis of Thaumarchaeota.

Main Results:

• Thaumarchaeota abundance generally decreased with depth, with an anomalous peak.
• Diverse thaumarchaeotal lineages were identified, including ammonia-oxidizing and non-oxidizing groups.
• A dominant benthic group (amoA-NP-γ) showed potential niche expansion from shallow waters.
• Intraspecies genomic variations were observed, differentiating benthic and pelagic groups.
• Adaptations included reduced genome size, altered metabolism, and modified substrate acquisition.

Conclusions:

• Hadal Thaumarchaeota exhibit microdiversification and niche partitioning.
• Genomic variations reflect adaptations to benthic versus pelagic deep-sea environments.
• This study provides novel insights into the evolution of life in extreme hadal zones.