PMID- 16703620
OWN - NLM
STAT- MEDLINE
DCOM- 20061005
LR  - 20061115
IS  - 0006-3592 (Print)
IS  - 0006-3592 (Linking)
VI  - 95
IP  - 1
DP  - 2006 Sep 5
TI  - Competition between Nitrospira spp. and Nitrobacter spp. in nitrite-oxidizing 
      bioreactors.
PG  - 169-75
AB  - In this work the question was addressed if in nitrite-oxidizing activated sludge 
      systems the environmental competition between Nitrobacter spp. and Nitrospira 
      spp., which only recently has been discovered to play a role in these systems, is 
      affected by the nitrite concentrations. Two parallel chemostats were inoculated 
      with nitrifying-activated sludge containing Nitrospira and operated under 
      identical conditions. After addition of Nitrobacter to both chemostats, the 
      nitrite concentration in the influent of one of the chemostats was increased such 
      that nitrite peaks in the bulk liquid of this reactor were detected. The other 
      chemostat served as control reactor, which always had a constant nitrite influent 
      concentration. The relative cellular area (RCA) of Nitrospira and Nitrobacter was 
      determined by quantitative fluorescence in situ hybridization (FISH). The nitrite 
      perturbation stimulated the growth of Nitrobacter while in the undisturbed 
      control chemostat Nitrospira dominated. Overall, the results of this experimental 
      study support the hypothesis that Nitrobacter is a superior competitor when 
      resources are abundant, while Nitrospira thrive under conditions of resource 
      scarcity. Interestingly, the dominance of Nitrobacter over Nitrospira, caused by 
      the elevated nitrite concentrations, could not be reverted by lowering the 
      available nitrite concentration to the original level. One possible explanation 
      for this result is that when Nitrobacter is present at a certain cell density it 
      is able to inhibit the growth of Nitrospira. An alternative explanation would be 
      that the length of the experimental period was not long enough to observe an 
      increase of the Nitrospira population.
CI  - (c) 2006 Wiley Periodicals, Inc.
FAU - Nogueira, Regina
AU  - Nogueira R
AD  - Centro de Engenharia Biologica-Universidade do Minho, Campus de Gualtar, 4700-057 
      Braga, Portugal. regina@deb.uminho.pt
FAU - Melo, Luis F
AU  - Melo LF
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Biotechnol Bioeng
JT  - Biotechnology and bioengineering
JID - 7502021
RN  - 0 (Nitrites)
RN  - 0 (Sewage)
SB  - IM
MH  - Bioreactors/*microbiology
MH  - Cell Proliferation
MH  - Coculture Techniques
MH  - Nitrites/metabolism
MH  - Nitrobacter/*cytology/*metabolism
MH  - Oxidation-Reduction
MH  - Sewage/*microbiology
MH  - Species Specificity
EDAT- 2006/05/17 09:00
MHDA- 2006/10/06 09:00
CRDT- 2006/05/17 09:00
PHST- 2006/05/17 09:00 [pubmed]
PHST- 2006/10/06 09:00 [medline]
PHST- 2006/05/17 09:00 [entrez]
AID - 10.1002/bit.21004 [doi]
PST - ppublish
SO  - Biotechnol Bioeng. 2006 Sep 5;95(1):169-75. doi: 10.1002/bit.21004.