Fungi Present in Antarctic Deep-Sea Sediments Assessed Using DNA Metabarcoding

Area of Science:

• Marine Mycology
• Deep-Sea Ecology
• Antarctic Research

Background:

• Deep-sea sediments are underexplored microbial habitats.
• Fungal communities play crucial roles in marine ecosystems.
• Antarctic deep-sea environments present unique ecological challenges.

Purpose of the Study:

• To assess fungal diversity in Southern Ocean deep-sea sediments.
• To identify dominant fungal taxa and their distribution across depths.
• To investigate potential terrestrial origins of deep-sea fungi.

Main Methods:

• Nuclear ribosomal DNA internal transcribed spacer 2 (ITS2) region sequencing.
• High-throughput sequencing (HTS) metabarcoding of sediment DNA.
• Bioinformatic analysis of fungal amplicon sequence variants (ASVs).

Main Results:

• Detected 263 fungal ASVs, dominated by Ascomycota and Basidiomycota.
• Identified dominant genera including Mortierella, Penicillium, and Cladosporium.
• Observed high fungal diversity and richness, with variations across sampled depths (250m to 1463m).
• Found globally distributed taxa, suggesting terrestrial input into marine sediments.
• Identified symbionts, decomposers, and potential pathogens within the fungal community.

Conclusions:

• Deep-sea sediments in the Southern Ocean are hotspots of fungal diversity.
• Fungal communities exhibit complex structures and varying distributions with depth.
• Terrestrial fungi may be transported to and persist in deep-sea environments.
• The detected fungal diversity includes ecologically and potentially clinically relevant taxa.