Denitrification Aligns with N2 Fixation in Red Sea Corals

Denitrification may potentially alleviate excess nitrogen (N) availability in coral holobionts to maintain a favourable N to phosphorous ratio in the coral tissue. However, little is known about the abundance and activity of denitrifiers in the coral holobiont. The present study used the nirS marker...

Full description

Saved in:
Bibliographic Details
Published in:Scientific reports 2019-12, Vol.9 (1), p.19460-19460, Article 19460
Main Authors: Tilstra, Arjen, El-Khaled, Yusuf C., Roth, Florian, Rädecker, Nils, Pogoreutz, Claudia, Voolstra, Christian R., Wild, Christian
Format: Article
Language:English
Subjects:
631/158/2452
631/158/2455
Bioavailability
Cell density
Corals
Denitrification
Environmental Sciences
Humanities and Social Sciences
Life Sciences
Microorganisms
multidisciplinary
Nitrates
Nitric oxide
Nitrogen
Nitrogen fixation
Nitrous oxide
Photosynthates
Photosynthesis
Prokaryotes
Science
Science (multidisciplinary)
Symbiodiniaceae
Taxonomy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Denitrification may potentially alleviate excess nitrogen (N) availability in coral holobionts to maintain a favourable N to phosphorous ratio in the coral tissue. However, little is known about the abundance and activity of denitrifiers in the coral holobiont. The present study used the nirS marker gene as a proxy for denitrification potential along with measurements of denitrification rates in a comparative coral taxonomic framework from the Red Sea: Acropora hemprichii , Millepora dichotoma , and Pleuractis granulosa . Relative nirS gene copy numbers associated with the tissues of these common corals were assessed and compared with denitrification rates on the holobiont level. In addition, dinitrogen (N 2 ) fixation rates, Symbiodiniaceae cell density, and oxygen evolution were assessed to provide an environmental context for denitrification. We found that relative abundances of the nirS gene were 16- and 17-fold higher in A. hemprichii compared to M. dichotoma and P. granulosa , respectively. In concordance, highest denitrification rates were measured in A. hemprichii , followed by M. dichotoma and P. granulosa . Denitrification rates were positively correlated with N 2 fixation rates and Symbiodiniaceae cell densities. Our results suggest that denitrification may counterbalance the N input from N 2 fixation in the coral holobiont, and we hypothesize that these processes may be limited by photosynthates released by the Symbiodiniaceae.
ISSN:2045-2322
2045-2322
DOI:10.1038/s41598-019-55408-z