Enrichment and characterization of ammonia-oxidizing archaea from the open ocean : phylogeny, physiology and stable isotope fractionation
Date
2011-03-14Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/5009As published
https://doi.org/10.1038/ismej.2011.58Abstract
Archaeal genes for ammonia oxidation are widespread in the marine environment, but
direct physiological evidence for ammonia oxidation by marine archaea is limited. We
report the enrichment and characterization of three strains of pelagic ammonia-oxidizing
archaea (AOA) from the north Pacific Ocean that have been maintained in laboratory
culture for over three years. Phylogenetic analyses indicate the three strains belong to a
previously identified clade of water column-associated AOA and possess 16S rRNA
genes and ammonia monooxygenase subunit a (amoA) genes highly similar (98-99%
identity) to those recovered in DNA and cDNA clone libraries from the open ocean. The
strains grow in natural seawater-based liquid medium while stoichiometrically converting
ammonium (NH4
+) to nitrite (NO2
-). Ammonia oxidation by the enrichments is only
partially inhibited by allylthiourea at concentrations known to inhibit cultivated
ammonia-oxidizing bacteria. The three strains were used to determine the nitrogen stable
isotope effect (15εNH3) during archaeal ammonia oxidation, an important parameter for
interpreting stable isotope ratios in the environment. Archaeal 15εNH3 ranged from 13-
41‰, within the range of that previously reported for ammonia-oxidizing bacteria.
Despite low amino acid identity between the archaeal and bacterial Amo proteins, their
functional diversity as captured by 15εNH3 is similar.
Description
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 5 (2011): 1796–1808, doi:10.1038/ismej.2011.58.