Ammonia-oxidizing archaea as main drivers of nitrification in cold-water sponges

Autor(en)

Regina Radax, Friederike Hoffmann, Hans Tore Rapp, Sven Leininger, Christa Schleper

Abstrakt

The association of archaea with marine sponges was first described 15 years ago and their role in the nitrification process in Mediterranean and tropical sponges has been suggested. Here we explore the occurrence and abundance of potential ammonia-oxidizing archaea (AOA) in four morphologically different cold-water sponges (Phakellia ventilabrum, Geodia barretti, Antho dichotoma and Tentorium semisuberites) from the sublittoral and upper bathyal zone [Correction added on 30 December 2011, after first online publication on 19 December 2011: The term 'mesopelagic zone' has been replaced.] of the Norwegian coast, and relate them to nitrification rates determined in laboratory incubations. Net nitrification rates, calculated from the sum of nitrite and nitrate release during 24 h, were up to 1880 nmol N cm(-3) day(-1); i.e. comparable with those measured in Mediterranean sponges. Furthermore, a high abundance of archaeal cells was determined by fluorescence in situ hybridizations (CARD-FISH) and quantitative PCR, targeting archaeal amoA genes (encoding the alpha subunit of ammonia monooxygenase). AmoA genes as well as amoA transcripts were either exclusively detectable from archaea or were orders of magnitudes higher in abundance than their bacterial counterparts. Phylogenetic analyses of AOA and bacterial nitrite oxidizers (genus Nitrospira) confirmed the presence of specific populations of nitrifying microorganisms in the sponge mesohyl, which either were affiliated with groups detected earlier in marine sponges or were typical inhabitants of cold-and deep-water environments. Estimated cell-specific nitrification rates for P. ventilabrum were 0.6 to 6 fmol N archaeal cell(-1) day(-1), thus comparable with planktonic organisms. Our results identify AOA as the major drivers of nitrification in four cold-water sponges, and indicate that these archaea may be considered as a relevant factor in nitrogen cycling in ocean regions with high sponge biomass.

Organisation(en)

Externe Organisation(en)

Max-Planck-Institut für marine Mikrobiologie, University of Bergen (UiB)

Journal

Environmental Microbiology

Band

14

Seiten

909-923

Anzahl der Seiten

15

ISSN

1462-2912

DOI

https://doi.org/10.1111/j.1462-2920.2011.02661.x

Publikationsdatum

2012

Peer-reviewed

Ja

ÖFOS 2012

106013 Genetik

Sustainable Development Goals

SDG 14 – Leben unter Wasser

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/67318a74-5508-45c5-a1f3-6a0f0cbfb99c