bioRxiv preprint doi: https://doi.org/10.1101/703868; this version posted July 16, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 DNA and RNA-SIP reveal Nitrospira spp. as key drivers of nitrification in 2 groundwater-fed biofilters 3 4 Running title: Nitrospira drives nitrification in groundwater-fed biofilters 5 Authors: Arda Gülay1,4*, Jane Fowler1, Karolina Tatari1, Bo Thamdrup3, Hans-Jørgen Albrechtsen1, 6 Waleed Abu Al-Soud2, Søren J. Sørensen2 and Barth F. Smets1* 7 1 Department of Environmental Engineering, Technical University of Denmark, Building 113, Miljøvej, 2800 8 Kgs Lyngby, Denmark. Phone: +45 45251600. FAX: +45 45932850. e-mail:
[email protected], jfow@ 9 env.dtu.dk,
[email protected],
[email protected]* 10 2 Department of Biology, University of Copenhagen, Universitetsparken 15, Building 1, 2100 Copenhagen, 11 Denmark. Phone: +45 35323710. FAX: +45 35322128. e-mail:
[email protected],
[email protected] 12 3 Nordic Center for Earth Evolution, Department of Biology, University of Southern Denmark, Campusvej 55, 13 5230 Odense, Denmark. Phone: +45 35323710. FAX: +45 35322128. e-mail:
[email protected] 14 4 Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States, 15 26 Oxford St, Cambridge, MA 02138, Phone: +1 (617)4951564. e-mail:
[email protected] 16 17 *Corresponding authors 18 Keywords: Nitrification, comammox, Nitrospira, DNA SIP, RNA SIP 19 bioRxiv preprint doi: https://doi.org/10.1101/703868; this version posted July 16, 2019.