We have located links that may give you full text access.
COMPARATIVE STUDY
JOURNAL ARTICLE
Functional robustness and gene pools of a wastewater nitrification reactor: comparison of dispersed and intact biofilms when stressed by low oxygen and low pH.
FEMS Microbiology Ecology 2008 October
The functional robustness of biofilms in a wastewater nitrification reactor, and the gene pools therein, were investigated. Nitrosomonas and Nitrosospira spp. were present in similar amounts (cloning-sequencing of ammonia-oxidizing bacteria 16S rRNA gene), and their estimated abundance (1.1 x 10(9) cells g(-1) carrier material, based on amoA gene real-time PCR) was sufficient to explain the observed nitrification rates. The biofilm also had a diverse community of heterotrophic denitrifying bacteria (cloning-sequencing of nirK). Anammox 16S rRNA genes were detected, but not archaeal amoA. Dispersed biofilms (DB) and intact biofilms (IB) were incubated in gas-tight reactors at different pH levels (4.5 and 5.5 vs. 6.5) while monitoring O(2) depletion and concentrations of NO, N(2)O and N(2) in the headspace. Nitrification was severely reduced by suboptimal O(2) concentrations (10-100 microM) and low pH (IB was more acid tolerant than DB), but the N(2)O/NO(3)(-) product ratio of nitrification remained low (<10(-3)). The NO(2)(-) concentrations during nitrification were generally 10 times higher in DB than in IB. Transient NO and N(2)O accumulation at the onset of denitrification was 10-10(3) times higher in DB than in IB (depending on the pH). The contrasting performance of DB and IB suggests that the biofilm structure, with anoxic/micro-oxic zones, helps to stabilize functions during anoxic spells and low pH.
Full text links
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app