| Title |
N2 fixation dominates nitrogen cycling in a mangrove fiddler crab holobiont |
| Authors |
Zilius, Mindaugas ; Bonaglia, Stefano ; Broman, Elias ; Chiozzini, Vitor Gonsalez ; Samuiloviene, Aurelija ; Nascimento, Francisco J.A ; Cardini, Ulisse ; Bartoli, Marco |
| DOI |
10.1038/s41598-020-70834-0 |
| Full Text |
|
| Is Part of |
Scientific reports.. London : Nature Publishing Group. 2020, vol. 10, no. 1, art. no. 13966, p. 1-13.. eISSN 2045-2322 |
| Keywords [eng] |
coastal ecosystems ; biogeochemical processes ; mangrove ecosystems |
| Abstract [eng] |
Mangrove forests are among the most productive and diverse ecosystems on the planet, despite limited nitrogen (N) availability. Under such conditions, animal-microbe associations (holobionts) are often key to ecosystem functioning. Here, we investigated the role of fiddler crabs and their carapace-associated microbial biofilm as hotspots of microbial N transformations and sources of N within the mangrove ecosystem. 16S rRNA gene and metagenomic sequencing provided evidence of a microbial biofilm dominated by Cyanobacteria, Alphaproteobacteria, Actinobacteria, and Bacteroidota with a community encoding both aerobic and anaerobic pathways of the N cycle. Dinitrogen (N2) fixation was among the most commonly predicted process. Net N fluxes between the biofilm-covered crabs and the water and microbial N transformation rates in suspended biofilm slurries portray these holobionts as a net N2 sink, with N2 fixation exceeding N losses, and as a significant source of ammonium and dissolved organic N to the surrounding environment. N stable isotope natural abundances of fiddler crab carapace-associated biofilms were within the range expected for fixed N, further suggesting active microbial N2 fixation. These results extend our knowledge on the diversity of invertebrate-microbe associations, and provide a clear example of how animal microbiota can mediate a plethora of essential biogeochemical processes in mangrove ecosystems. |
| Published |
London : Nature Publishing Group |
| Type |
Journal article |
| Language |
English |
| Publication date |
2020 |
| CC license |
|
