The largely neglected ecological role of oceanic pelagic fungi

A fungi hotspot deep down the ocean: explaining the presence ofGjaerumia minorin Equatorial Pacific bathypelagic waters

“…Saprotrophic fungi degrade and recycle organic matter with extracellular enzymes 6 , in particular, it has been reported that the abundance of CAZymes (Carbohydrate Active enZymes) increases toward mesopelagic waters 7 pointing to the central role of fungal catabolism in aphotic environments. A similar pattern was also detected for genes related to protein degradation 8 . The utilization of extracellular enzymes is a more effective digestion strategy if associated with a particulate-attached lifestyle and, actually, in bathypelagic waters fungi are main colonizers of marine snow, exceeding in some cases the biomass of bacteria 9 .…”

Planktonic Marine Fungi: A Review

“…The quantification of biomass is a fundamental prerequisite to quantify microbial contributions to marine biogeochemical cycles. While marine fungi are commonly encountered in DNA‐based studies spanning global oceans (Amend et al., 2019; Breyer & Baltar, 2023; Morales et al., 2019) there remains a significant lack of comprehensive information concerning their abundances and biomass. Nonetheless, this enigmatic kingdom can exhibit biomass levels that surpass prokaryotes during phytoplankton blooms (Gutiérrez et al., 2011; Hassett et al., 2019) and associated with bathypelagic marine snow (Bochdansky et al., 2017).…”

“…Despite the widespread application of metabarcoding surveys of marine microbial communities, the number of studies that examined open ocean fungal diversity remains very small. A review by Breyer and Baltar (2023) provided an up‐to‐date and comprehensive summary of metabarcoding surveys of planktonic fungi. Of the 26 studies summarized by Breyer and Baltar (2023), only 11 included samples from the open ocean (Bass et al., 2007; Debeljak & Baltar, 2023; Hassett et al., 2017, 2019; Jeffries et al., 2016; W. Li et al., 2019; Morales et al., 2019; Orsi et al., 2022; Peng & Valentine, 2021; Tisthammer et al., 2016; X. Wang et al., 2014).…”

“…A review by Breyer and Baltar (2023) provided an up‐to‐date and comprehensive summary of metabarcoding surveys of planktonic fungi. Of the 26 studies summarized by Breyer and Baltar (2023), only 11 included samples from the open ocean (Bass et al., 2007; Debeljak & Baltar, 2023; Hassett et al., 2017, 2019; Jeffries et al., 2016; W. Li et al., 2019; Morales et al., 2019; Orsi et al., 2022; Peng & Valentine, 2021; Tisthammer et al., 2016; X. Wang et al., 2014). Most of these studies focused on one region of the global ocean during one field campaign, while TARA Oceans was the primary source of fungal diversity data providing larger coverage of the global ocean.…”

“…Currently, “marine fungi” are defined as any fungi recovered repeatedly from marine habitats that are able to grow and/or sporulate in marine environments, form symbiotic relationships with other marine organisms, adapt and evolve at the genetic level, or are active metabolically in marine environments (Pang et al., 2016). Driven by rising interests from multiple disciplines in the past decade, a number of reviews, books, and perspective articles have provided synthesis of our knowledge derived from over a century of research on marine fungi (Amend et al., 2019; Breyer & Baltar, 2023; Burgaud et al., 2022; Cunliffe, 2023; Gladfelter et al., 2019; Gonçalves, Esteves, & Alves, 2022; Grossart et al., 2019; Hassett et al., 2019; Jones & Pang, 2012; Kempken, 2023; Raghukumar, 2017a; Rédou et al., 2016; Richards et al., 2012; Sen et al., 2022). Planktonic marine fungi refer to those (in the form of spores, yeasts, mycelia, sporangia or other fungal propagules) that are found to be active in suspension or attached to particles, substrates or hosts in the ocean (G. Wang et al., 2012).…”