Potential and expression of carbohydrate utilization by marine fungi in the global ocean

Author(s)
Federico Baltar, Zihao Zhao, Gerhard J Herndl
Abstract

BACKGROUND: Most of the research on the cycling of carbon in the open-ocean has focused on heterotrophic prokaryotes and eukaryotic phytoplankton, but the role of pelagic fungi remains largely enigmatic.

METHODS: Here, we performed a global-ocean multi-omics analysis of all pelagic fungal carbohydrate-active enzymes (CAZymes), key enzymes in the carbon cycling. We studied the occurrence, expression, diversity, functional classification, and taxonomic affiliation of the genes encoding all pelagic fungal CAZymes from the epi- and mesopelagic realm.

RESULTS: Pelagic fungi are active in carbohydrate degradation as indicated by a high ratio of CAZymes transcripts per gene. Dothideomycetes in epipelagic and the Leotiomycetes in mesopelagic waters (both from the phylum Ascomycota) are the main pelagic fungi responsible for carbohydrate degradation in the ocean. The abundance, expression, and diversity of fungal CAZymes were higher in the mesopelagic than in the epipelagic waters, in contrast to the distribution pattern of prokaryotic CAZymes.

CONCLUSIONS: Our results reveal a widespread utilization of different types of CAZymes by pelagic fungi, uncovering an active and hitherto largely unexplored participation of fungi in the pelagic C cycling, where pelagic prokaryotes and fungi occupy different ecological niches, and fungi becoming relatively more important with depth. Video abstract.

Organisation(s)
Functional and Evolutionary Ecology, Research Platform Vienna Metabolomics Center
External organisation(s)
Utrecht University
Journal
Microbiome
Volume
9
ISSN
2049-2618
DOI
https://doi.org/10.1186/s40168-021-01063-4
Publication date
05-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
106026 Ecosystem research, 106021 Marine biology
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/potential-and-expression-of-carbohydrate-utilization-by-marine-fungi-in-the-global-ocean(164c1222-fc8b-4931-955e-e2c8970927d4).html