Open AccessThe depth‐specific significance and relative abundance of anaerobic ammonium‐oxidizing bacteria in estuarine sediments ( M edway E stuary, UK )
Author(s) -
Rooks Christine,
Schmid Markus C.,
Mehsana Wahida,
Trimmer Mark
Publication year - 2012
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2011.01266.x
Subject(s) - anammox , estuary , sediment , biology , abundance (ecology) , ammonium , population , environmental chemistry , relative species abundance , ecology , denitrification , oceanography , environmental science , nitrogen , chemistry , denitrifying bacteria , geology , paleontology , demography , organic chemistry , sociology
Variations in the overall and depth‐specific significance of anammox were measured using 15 N isotope experiments in both bioirrigated and undisturbed sediments of the Medway Estuary, UK . This was performed over two surveys, alongside FISH experiments, to identify and track shifts in the relative abundance of anammox organisms with depth. In Survey 1 (initially screening for the presence of anammox), the potential for anammox ( ra ) decreased from 32% upstream to 6% downstream. In Survey 2, depth‐specific values of ra varied between a maximum of 37% upstream and a minimum of 4% downstream. This was linked to a small population of anammox organisms accounting for < 1–8% of total bacteria with depth in Survey 1 and < 1–3% in Survey 2. The relationship between the relative abundance of anammox cells and the potential contribution of anammox to total N 2 production did not however correlate. In Survey 2, infaunal disruption of the sediment substrata, and concomitant fluctuations of O 2 over depth, did not appear to inhibit the potential for anammox, even at the most bioturbated site. Moreover, deficits detected in the retrieval of 15 N gas from denitrification in Survey 2 may imply potential links between dissimilatory nitrate reduction to ammonium and anammox in estuarine sediments.