Skip to main content

Double-check of dissimilatory nitrate reduction to either ammonium or dinitrogen in aquatic habitats

Objective

The proposed project focuses on the so far neglected comparative investigation of denitrification and DNRA (Dissimilatory Nitrate Reduction to Ammonium), two benthic microbial processes of great importance for nitrogen cycling in aquatic ecosystems.

We aim at moving DNRA more into the spotlight, because:
(1) its metabolic control and phylogenetic diversity is understudied compared to denitrification; and
(2) its environmental importance will increase relative to denitrification due to the excessive water use in aquaculture and desalination.

Anthropogenic and environmental factors that change the partitioning between the two processes will also affect the ratio of nitrogen removal (denitrification) and nitrogen retention (DNRA) from and within the ecosystem. Therefore, we expect that a better understanding of the metabolic control and phylogenetic diversity of DNRA will aid in developing management strategies for handling nitrogenous pollution of aquatic ecosystems.

In an integrated approach using the contemporary techniques of microbial ecology we aim at:
(1) measuring rates of denitrification & DNRA simultaneously and at high spatial resolution in marine sediments, aquaculture and desalination systems;
(2) determining community structure and gene expression of denitrifying & DNRA-performing bacteria in natural sediments; and
(3) correlating rates with presence & metabolic status of denitrifying & DNRA-performing bacteria, and with spatial gradients of environmental factors (H2S & T OC).

The field investigations will be complemented by laboratory incubations in which the short-term metabolic response and the long-term community shifts of denitrifying & DNRA-performing bacteria can be studied. Additionally, denitrifying & DNRA-performing strains will be isolated from the field-collected samples and screened for co-occurrence of functional genes of both metabolic pathways.

Call for proposal

FP6-2004-MOBILITY-11
See other projects for this call

Coordinator

MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V./MAX-PLANCK-INSTITUT FUER MARINE MIKROBIOLOGIE
Address
Hofgartenstrasse
Muenchen
Germany