Potentially Active Iron, Sulfur, and Sulfate Reducing Bacteria in Skagerrak and Bothnian Bay Sediments

Author(s)
Carolina Reyes, Dominik Schneider, Andrea Thürmer, Ajinkya Kulkarni, Marko Lipka, Saar Sztejrenszus, Michael E. Böttcher, Michael Friedrich
Abstract

In many marine surface sediments, the reduction of manganese (Mn) and iron (Fe) oxides is obscured by sulfate reduction, which is regarded as the predominant anaerobic microbial respiration process. However, many dissimilatory sulfate and sulfur reducing microorganisms are known to utilize alternative electron acceptors such as metal oxides. In this study, we tested whether sulfate and sulfur reducing bacteria are linked to metal oxide reduction based on biogeochemical modeling of porewater concentration profiles of Mn2+ and Fe2+ in Bothnian Bay (BB) and Skagerrak (SK) sediments. Steady-state modeling of Fe2+ and Mn2+ porewater profiles revealed zones of net Fe (0–9 cm BB; ∼10 and 20 cm SK) and Mn (0–5 cm BB; 2–8 cm SK) species transformations. 16S rRNA pyrosequencing analysis of the in-situ community showed that Desulfobacteraceae, Desulfuromonadaceae and Desulfobulbaceae were present in the zone of Fe-reduction of both sediments. Rhodobacteraceae were also detected at high relative abundance in both sediments. BB sediments appeared to harbor a greater diversity of potential Fe-reducers compared to SK. Additionally, when the upper 10 cm of sediment from the SK was incubated with lepidocrocite and acetate, Desulfuromonas was the dominant bacteria. Real-time quantitative polymerase chain reaction (qPCR) results showed decreasing dsrA gene copy numbers with depth coincided with decreased Fe-reduction activity. Our results support the idea that sulfur and sulfate reducing bacteria contribute to Fe-reduction in the upper centimeters of both sediments.

Organisation(s)
External organisation(s)
Universität Bremen, Georg-August-Universität Göttingen, Leibniz-Institut für Ostseeforschung, Max-Planck-Institut für terrestrische Mikrobiologie
Journal
Geomicrobiology Journal: an international journal of geomicrobiology and microbial biogeochemistry
Volume
34
Pages
840-850
No. of pages
11
ISSN
0149-0451
DOI
https://doi.org/10.1080/01490451.2017.1281360
Publication date
2017
Peer reviewed
Yes
Austrian Fields of Science 2012
105904 Environmental research, 106022 Microbiology
Keywords
ASJC Scopus subject areas
General Environmental Science, Microbiology, Earth and Planetary Sciences (miscellaneous), Environmental Chemistry
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/74f15399-b049-479a-9820-f69f60f1f4e4