title: Denitrification and the denitrifier community in coastal microbial mats.
abstract: Denitrification was measured in three structurally different coastal microbial mats by using the stable isotope technique. The composition of the denitrifying community was determined by analyzing the nitrite reductase (nirS and nirK) genes using clone libraries and the GeoChip. The highest potential rate of denitrification (7.0 ± 1.0 mmol N m(-2) d(-1)) was observed during summer at station 1 (supra-littoral). The rates of denitrification were much lower in the stations 2 (marine) and 3 (intermediate) (respectively 0.1 ± 0.05 and 0.7 ± 0.2 mmol N m(-2) d(-1)) and showed less seasonality when compared to station 1. The denitrifying community at station 1 was also more diverse than that at station 2 and 3, which were more similar to each other than either of these stations to station 1. In all three stations, the diversity of both nirS and nirK denitrifiers was higher in summer when compared to winter. The location along the tidal gradient seems to determine the composition, diversity and activity of the denitrifier community, which may be driven by salinity, nitrate/nitrite and organic carbon. Both nirS and nirK denitrifiers are equally present and therefore they are likely to play a role in the denitrification of the microbial mats studied.
authors.affiliation: Department of Marine Microbiology, Royal Netherlands Institute of Sea Research, PO Box 140, 4400 AC Yerseke, The Netherlands.
authors.forename: Haoxin
authors.initials: H
authors.lastname: Fan
authors.affiliation: Department of Marine Microbiology, Royal Netherlands Institute of Sea Research, PO Box 140, 4400 AC Yerseke, The Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: Bolhuis
authors.affiliation: Department of Marine Microbiology, Royal Netherlands Institute of Sea Research, PO Box 140, 4400 AC Yerseke, The Netherlands Department of Aquatic Microbiology, Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94248, 1090 GE Amsterdam, The Netherlands Lucas.Stal@nioz.nl.
authors.forename: Lucas J
authors.initials: LJ
authors.lastname: Stal
mesh_terms: D000595:Amino Acid Sequence; D059001:Aquatic Organisms / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D058440:Denitrification / Q000235:genetics*; D064307:Microbiota / Q000235:genetics; D009572:Nitrite Reductases / Q000235:genetics*; D009792:Oceans and Seas; D054712:Salinity; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D009572:Nitrite Reductases
keywords: denitrification; microbial mat; nirK; nirS