Use of immunofluorescence technique for studying a Nitrobacter population from wastewater treatment plant following discharge in river sediments: First experimental data

Nitrobacter colonies, associated with particles in water treatment plant discharges, and their survival after discharge, were studied to assess their inoculation potential in rivers. Diversity and location of Nitrobacter colonies in floc particles (size range 0.45–500 μm) were studied using immunofluoresence methods. The qualitative and quantitative composition of Nitrobacter colonies, expressed by five of its serotypes (AG, DE30, W, LL and X14) is not related to the size of the particles on which they fix. This lack of correlation makes it possible to assess the overall impact of a wastewater treatment plant effluent on a sedimentary area in a microcosm. Nitrobacter combined with discharge particles (1010 cells•g−1 dry floc) can settle in freshwater sediments in a week (106 cells•g−1 dry sediment). If discharge is continuous, the Nitrobacter cells carried in the effluent could thus colonize river sediments.