English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The change of activity and abundance of Nitrosospira and Nitrospira spp. along a bulk water gradient in a nitrifying fluidized bed reactor was analyzed by a combination of microsensor measurements and fluorescence in situ hybridization. Nitrifying bacteria were immobilized in bacterial aggregates that remained in fixed positions within the reactor column due to the flow regimen. Nitrification occurred in a narrow zone of 100 to 150 microm on the surface of these aggregates, the same layer that contained an extremely dense community of nitrifying bacteria. The central part of the aggregates was inactive, and significantly fewer nitrifiers were found there. Under conditions prevailing in the reactor, i.e., when ammonium was limiting, ammonium was completely oxidized to nitrate within the active layer of the aggregates, the rates decreasing with increasing reactor height. To analyze the nitrification potential, profiles were also recorded in aggregates subjected to a short-term incubation under elevated substrate concentrations. This led to a shift in activity from ammonium to nitrite oxidation along the reactor and correlated well with the distribution of the nitrifying population. Along the whole reactor, the numbers of ammonia-oxidizing bacteria decreased, while the numbers of nitrite-oxidizing bacteria increased. Finally, volumetric reaction rates were calculated from microprofiles and related to cell numbers of nitrifying bacteria in the active shell. Therefore, it was possible for the first time to estimate the cell-specific activity of Nitrosospira spp. and hitherto-uncultured Nitrospira-like bacteria in situ.

applied and environmental microbiology

Microscale Distribution of Populations and Activities of <i>Nitrosospira</i> and <i>Nitrospira</i> spp. along a Macroscale Gradient in a Nitrifying Bioreactor: Quantification by In Situ Hybridization and the Use of Microsensors

Microscale Distribution of Populations and Activities of Nitrosospira and Nitrospira spp. along a Macroscale Gradient in a Nitrifying Bioreactor: Quantification by In Situ Hybridization and the Use of Microsensors