Fungal diversity in deep-sea sediments from the Magellan seamounts as revealed by a metabarcoding approach targeting the ITS2 regions

Abstract

Recent reports have revealed diverse and abundant fungal communities in the deep-sea biosphere, while their composition, distribution, and variations in seamount zones are poorly understood. Using a metabarcoding approach targeting the ITS2 regions, we present the structure of the fungal community in 18 sediment samples from the Magellan seamount area of the northwest Pacific. A total of 1,979 fungal OTUs was obtained, which were taxonomically assigned to seven phyla, 17 classes, 43 orders, 7 families, and 98 genera. The majority of these OTUs were affiliated to Basidiomycota (873 OTUs, 44.11% of total OTUs) and Ascomycota (486 OTUs, 24.56% of total OTUs), followed by other five minor phyla (Mortierellomycota, Chytridiomycota, Mucoromycota, Glomeromycota, and Monoblepharidomycota). Sordriomycetes is the most abundant class, followed by Eurotiomycetes, and Dothideomycetes. Five genera were common in most of the samples, including worldwide reported genera Aspergillus, Cladosporium, Fusarium, Chaetomium, and Penicillium. The environmental data we collected (sampling depth, sampling location latitude and longitude, organic carbon content, and organic nitrogen content in the sediment) had no significant influence on the composition and distribution of fungal communities. Our findings provide valuable information for understanding the distribution and potential ecological functions of fungi in the deep-sea sediments of the Magellan seamounts.

Fungal Diversity in Sediments From Deep-Sea Extreme Ecosystems: Insights Into Low- and High-Temperature Hydrothermal Vents, and an Oxygen Minimum Zone in the Southern Gulf of California, Mexico

“…Our findings on the dominant occurrence of Ascomycota, followed by Basidiomycota in all the studied sites, agrees with a plethora of investigations in hadal trenches (Xu et al, 2019;Gao et al, 2020), deep-sea sediments (Damare et al, 2006;Singh et al, 2012;Zhang et al, 2014Zhang et al, , 2016, OMZs (Jebaraj et al, 2010), methane hydrate-bearing deep-sea marine sediments (Lai et al, 2007), hydrothermal vents (Burgaud et al, 2009;Le Calvez et al, 2009), and chemosynthetic whale falls (Nagano et al, 2020). Furthermore, the occurrence of Glomeromycota as a minor proportion of the community in the Pescadero Transform Fault (PV_1), resembles former findings reporting this phylum as a component of fungal vent communities (Le Nagano et al, 2010;Nagahama et al, 2011;Luo et al, 2020). Largely, these results suggest that despite distinctive extreme conditions of the investigated systems, they host a considerable fungal diversity in higher taxonomic categories.…”

Fungal Diversity and Composition of the Continental Solar Saltern in Añana Salt Valley (Spain)

“…In particular, Ascomycota members were more frequently detected than Basidiomycota. These results were also previously observed in deep ocean ecosystems [34], saline soils [35], deep-sea sediments [36,37], and in other salterns [14]. Furthermore, Wei et al [15] have recently described the fungal composition of a millennial coastal saltern in South China, where the fungal community was different from that which was detected in the continental saltern of this study.…”

Environmental factors shaping bacterial, archaeal and fungal community structure in hydrothermal sediments of Guaymas Basin, Gulf of California

“…Abundant Rhizophlyctidales and Spizellomycetales 18S rRNA gene sequences from high-altitude soils group with environmental sequences from diverse locations, including deep anoxic marine sediments of Cariaco Basin and high-altitude soils [ 116 , 117 ]. OTUs belonging to Spizellomycetales were identified from deep-sea sediments in the Magellan seamounts [ 118 ], although members of this group are thought to be mainly of terrestrial origin. Their survival and/or activity in the deep sea remain open questions.…”