Changes in the Potential Activity of Nitrite Reducers and the Microbial Community Structure After Sediment Dredging and Plant Removal in the Empuriabrava FWS-CW.

Changes in the Potential Activity of Nitrite Reducers and the Microbial Community Structure After Sediment Dredging and Plant Removal in the Empuriabrava FWS-CW.
Microb Ecol. 2019 Sep 05;:
Authors: Hernández-Del Amo E, Ramió-Pujol S, Gich F, Trias R, Bañeras L
Abstract
In constructed wetlands (CW), denitrification usually accounts for > 60% of nitrogen removal and is supposedly affected by wetland management practices, such as dredging (and plant removal). These practices cause an impact in sediment properties and microbial communities living therein. We have quantified the effects of a sediment dredging event on dissimilatory nitrite reduction by analysing the structure and activities of the microbial community before and after the event. Potential rates for nitrate reduction to ammonia and denitrification were in accordance with changes in the physicochemical conditions. Denitrification was the predominant pathway for nitrite removal (> 60%) and eventually led to the complete removal of nitrate. On the contrary, dissimilatory nitrite reduction to ammonia (DNRA) increased from 5 to 18% after the dredging event. Both actual activities and abundances of 16S rRNA, nirK and nirS significantly decreased after sediment dredging. However, genetic potential for denitrification (qnirS + qnirK/q16S rRNA) remained unchanged. Analyses of the 16S rRNA gene sequences revealed the importance of vegetation in shaping microbial communit...

Source: Microbial Ecology - September 4, 2019 Category: Microbiology Authors: Hernández-Del Amo E, Ramió-Pujol S, Gich F, Trias R, Bañeras L Tags: Microb Ecol Source Type: research