Inhibition of biofilm populations of Nitrosomonas europaea

Abstract

The influence of surface attachment and growth on inhibition of the ammonia oxidizing bacterium, Nitrosomonas europaea, by nitrapyrin was investigated in liquid culture in the presence and absence of glass slides. Significant attachment to glass slides occurred in the absence of ammonia, but the extent of attachment was not affected by nitrapyrin, nor by previous culture of cells in medium containing nitrapyrin. The presence of glass slides affected neither the specific growth rate of N. europaea, measured by changes in nitrite concentration, nor inhibition by nitrapyrin. Inhibitory effects of nitrapyrin on increases in nitrite concentration and in free cell concentration were similar, but greater effects were observed on changes in attached cell concentration. Established biofilms on glass slides grew at a lower specific growth rate than freely suspended cells. Both biofilm cells, and those detached from the biofilm, were protected from inhibition. A mechanism for protection of biofilm populations is proposed involving reduced sensitivity of slowly growing cells producing extracellular polymeric material.

Dynamics of viable nitrifier community and nutrient availability in dry tropical forest habitat as affected by cultivation and soil texture

“…In soil, where majority of particles are negatively charged and cells of nitrite-oxidizing bacteria may be less firmly attached than those of ammonia-oxidizing bacteria (Prosser, 1989). Clay minerals strongly adsorb ammonium ions, resulting in preferential colonization of such surfaces by ammonia-oxidizing bacteria which, however, realize reduced growth rate due to localized depletion of ammonia at the surface (Powell and Prosser, 1992). Although the concentration of ammonia adsorbed to clay minerals offers the potential for increased rates of ammonia oxidation, it may be counteracted by localized increases in H + concentration at the same anionic site (Prosser, 1989).…”

Inhibition of phenol on the rates of ammonia oxidation by Nitrosomonas europaea grown under batch, continuous fed, and biofilm conditions

“…europaea has been examined under different growth states to study inhibition of NH 3 oxidation (Chandran and Love, 2008;Radniecki et al, 2009). A study of N. europaea biofilms reported that established biofilms were less inhibited by the nitrification inhibitor nitrapyrin and exhibited reduced growth rates compared to suspended cells (Powell and Prosser, 1992). Additionally, exponential cells of N. europaea exhibited greater inhibition of NH 3 oxidation when exposed to nitrapyrin compared to stationary-phase cultures (Powell and Prosser, 1986).…”

Epiphyton as a Niche for Ammonia-Oxidizing Bacteria: Detailed Comparison with Benthic and Pelagic Compartments in Shallow Freshwater Lakes

“…For example, compared with the water column of aquatic environments, solid-phase habitats, such as sediment, particulate material, and aquatic macrophytes, seemed to be differently (35,40,50) and more densely populated with nitrifying bacteria (12,33,34). This surface-attached growth has been proposed to offer resilience against environmental constraints (41). Moreover, the formation of a biofilm on surfaces provides significant benefits for AOB of the Nitrosomonas lineages that are able to produce extracellular polymeric materials.…”