Nitrite concentration influences the population structure of Nitrospira‐like bacteria

Abstract

Chemolithoautotrophic nitrite oxidizers of the genus Nitrospira are a monophyletic but diverse group of organisms, are widely distributed in many natural habitats, and play a key role in nitrogen elimination during biological wastewater treatment. Phylogenetic analyses of cloned 16S rRNA genes and fluorescence in situ hybridization with newly developed rRNA-targeted oligonucleotide probes revealed coexistence of uncultured members of sublineages I and II of the genus Nitrospira in biofilm and activated sludge samples taken from nitrifying wastewater treatment plants. Quantitative microscopic analyses of their spatial arrangement relative to ammonia oxidizers in the biofilm and activated sludge flocs showed that members of the Nitrospira sublineage I occurred significantly more often in immediate vicinity to ammonia oxidizers than would be expected from random community assembly while such a relationship was not observed for Nitrospira sublineage II. This spatial distribution suggested a niche differentiation of these coexisting Nitrospira populations with respect to their preferred concentrations of nitrite. This hypothesis was tested by mathematical modelling of nitrite consumption and resulting nitrite gradients in nitrifying biofilms and by quantifying the abundance of sublineage I and II Nitrospira in activated sludge during incubations with nitrite in different concentrations. Consistent with the observed localization patterns, a higher nitrite concentration selected for sublineage I but suppressed sublineage II Nitrospira.

Interactions between Thaumarchaea, Nitrospira and methanotrophs modulate autotrophic nitrification in volcanic grassland soil

“…for autotrophic nitrite oxidation which is consistent with previous reports (Freitag et al, 2005;Xia et al, 2011). Differences in autotrophic growth of the Nitrospira sublineage I OTU 181 between HAT and LAT microcosms supports the report on a preference for higher nitrite concentrations of this sublineage (Maixner et al (2006). In contrast we found the autotrophic activity of a Nitrospira sublineage II phylotype increased upon addition of more NH 4 þ .…”

Structure and function of the microbial community in a full-scale enhanced biological phosphorus removal plant

“…LGCmix [equimolar concentrations of LGC354A, LGC354B and LGC354C (Meier et al, 1999)], TM7905 (Hugenholtz et al, 2001), Ntspa1413 (Maixner et al, 2006), HoAc1402 (Juretschko et al, 2002), CFX1223 and GNSB-941 (Bjornsson et al, 2002), Actino-221, Actino-651 (Kong et al, 2005), and PAOmix [equimolar concentrations of PAO651, PAO462 and PAO846 (Crocetti et al, 2000)], GB_G1 (GAOQ989) (Crocetti et al, 2002) and GB_G2, GB_1&2, GB_3, GB_4, GB_5, GB_7 (Kong et al, 2002), GB_6 [Gam1019 (Nielsen et al, 1999)], Cluster 6a-192 (Adamczyk et al, 2003), ZRA23a (Rossello-Mora et al, 1995), Azo644 (Hess et al, 1997), Thau-646 (Lajoie et al, 2000), Aqs997 (Thomsen et al, 2004), Sap309 (Schauer & Hahn, 2005), CF319a and CF319b (Manz et al, 1996) were used for FISH. All the probes, except the EUBmix, which was labelled with FLUOS, were labelled with either Cy3 or Cy5 (only for specificity check).…”

Disturbance and temporal partitioning of the activated sludge metacommunity

“…In addition to the importance of activated sludge in modern sanitation, these systems are uniquely suited for whole-ecosystem scale experimentation due to the tight controls on chemical, physical and biological processes (Daims et al, 2006). As a model system for microbial ecology, research on activated sludge has greatly informed our understanding of microbe-microbe interactions (Wagner ,2002;Daims et al, 2006;Maixner et al, 2006), undiscovered biochemistry (Strous et al, 2006;Maixner et al, 2008;Lü cker et al, 2010;He and McMahon, 2011;Sorokin et al, 2012) and community assembly theory (Sloan et al, 2007;Ofiteru et al, 2010). However, little work has focused on the ecological consequences of press (that is, prolonged) disturbances on microbial diversity and the extent of compositional versus environmental effects on ecosystem function (Allison and Martiny, 2008).…”