Nitrogen Metabolism Genes from Temperate Marine Sediments

Author(s)
Carolina Reyes, Dominik Schneider, Andrea Thürmer, Marko Lipka, Michael Böttcher, Michael Friedrich
Abstract

In this study, we analysed metagenomes along with biogeochemical profiles from Skagerrak (SK) and Bothnian Bay (BB) sediments, to trace the prevailing nitrogen pathways. NO3− was present in the top 5 cm below the sediment-water interface at both sites. NH4+ increased with depth below 5 cm where it overlapped with the NO3− zone. Steady-state modelling of NO3− and NH4+ porewater profiles indicates zones of net nitrogen species transformations. Bacterial protease and hydratase genes appeared to make up the bulk of total ammonification genes. Genes involved in ammonia oxidation (amo, hao), denitrification (nir, nor), dissimilatory NO3− reduction to NH4+ (nfr and otr) and in both of the latter two pathways (nar, nap) were also present. Results show ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are similarly abundant in both sediments. Also, denitrification genes appeared more abundant than DNRA genes. 16S rRNA gene analysis showed that the relative abundance of the nitrifying group Nitrosopumilales and other groups involved in nitrification and denitrification (Nitrobacter, Nitrosomonas, Nitrospira, Nitrosococcus and Nitrosomonas) appeared less abundant in SK sediments compared to BB sediments. Beggiatoa and Thiothrix 16S rRNA genes were also present, suggesting chemolithoautotrophic NO3− reduction to NO2− or NH4+ as a possible pathway. Our results show the metabolic potential for ammonification, nitrification, DNRA and denitrification activities in North Sea and Baltic Sea sediments.

Organisation(s)
External organisation(s)
Universität Bremen, Georg-August-Universität Göttingen, Leibniz-Institut für Ostseeforschung
Journal
Marine Biotechnology
Volume
19
Pages
175-190
No. of pages
16
ISSN
1436-2228
DOI
https://doi.org/10.1007/s10126-017-9741-0
Publication date
2017
Peer reviewed
Yes
Austrian Fields of Science 2012
105904 Environmental research, 106022 Microbiology
Keywords
ASJC Scopus subject areas
Aquatic Science, Biotechnology
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/a325f085-9b7b-46bf-81ab-cd6ab29d6830