PMID- 30824434
OWN - NLM
STAT- MEDLINE
DCOM- 20200409
LR  - 20200409
IS  - 1098-5336 (Electronic)
IS  - 0099-2240 (Print)
IS  - 0099-2240 (Linking)
VI  - 85
IP  - 9
DP  - 2019 May 1
TI  - Low Temperature and Neutral pH Define "Candidatus Nitrotoga sp." as a Competitive 
      Nitrite Oxidizer in Coculture with Nitrospira defluvii.
LID - 10.1128/AEM.02569-18 [doi]
LID - e02569-18
AB  - Nitrification is an essential process for N removal in activated sludge to avoid 
      toxicity of ammonium and nitrite. Besides Nitrospira, "Candidatus Nitrotoga" has 
      been identified as a key nitrite-oxidizing bacterium (NOB) performing the second 
      step of nitrification, nitrite oxidation to nitrate, in wastewater treatment 
      plants (WWTPs). However, the driving forces for the dominance of Nitrotoga in 
      certain plants have often remained unclear and could not be explained solely by 
      temperature effects. In this study, we characterized the physiology of the 
      ammonium-dependent Nitrotoga sp. BS with regard to temperature and pH variations 
      and evaluated its competitiveness against Nitrospira defluvii Both NOB originated 
      from the same WWTP and shared a comparable pH optimum of 7.3. Based on these 
      results, coculturing experiments with these NOB were performed in batch reactors 
      operated at either 17 degrees C or 22 degrees C to compare their abundances under optimal (pH 
      7.4) or suboptimal (pH 6.4) conditions using 1 mM nitrite. As revealed by 
      quantitative PCR (qPCR), fluorescence in situ hybridization (FISH), and 16S 
      amplicon sequencing, Nitrotoga sp. BS was clearly favored by its optimal growth 
      parameters and dominated over Ns. defluvii at pH 7.4 and 17 degrees C, whereas a pH of 
      6.4 was more selective for Ns. defluvii Our synthetic communities revealed that 
      niche differentiation of NOB is influenced by a complex interaction of 
      environmental parameters and has to be evaluated for single species.IMPORTANCE 
      "Ca. Nitrotoga" is a NOB of high environmental relevance, but physiological data 
      exist for only a few representatives. Initially, it was detected in specialized 
      niches of low temperature and low nitrite concentrations, but later on, its 
      ubiquitous distribution revealed its critical role for N removal in engineered 
      systems like WWTPs. In this study, we analyzed the competition between Nitrotoga 
      and Nitrospira in bioreactors and identified conditions where the K strategist 
      Ns. defluvii was almost replaced by Nitrotoga sp. BS. We show that the pH value 
      is an important factor that regulates the composition of the nitrite-oxidizing 
      enrichment with a dominance of Nitrotoga sp. BS versus Ns. defluvii at a neutral 
      pH of 7.4 in combination with a temperature of 17 degrees C. The physiological diversity 
      of novel Nitrotoga cultures improves our knowledge about niche differentiation of 
      NOB with regard to functional nitrification under suboptimal conditions.
CI  - Copyright (c) 2019 American Society for Microbiology.
FAU - Wegen, Simone
AU  - Wegen S
AD  - Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, 
      Germany.
FAU - Nowka, Boris
AU  - Nowka B
AD  - Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, 
      Germany.
FAU - Spieck, Eva
AU  - Spieck E
AD  - Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, 
      Germany eva.spieck@uni-hamburg.de.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20190418
PL  - United States
TA  - Appl Environ Microbiol
JT  - Applied and environmental microbiology
JID - 7605801
RN  - 0 (Nitrites)
RN  - Nitrospira defluvii
SB  - IM
MH  - Bacteria/*metabolism
MH  - Bioreactors
MH  - Coculture Techniques
MH  - Cold Temperature
MH  - Gallionellaceae/*physiology
MH  - Hydrogen-Ion Concentration
MH  - Nitrites/*metabolism
MH  - Oxidation-Reduction
PMC - PMC6495747
OTO - NOTNLM
OT  - Nitrospira
OT  - Nitrotoga
OT  - activated sludge
OT  - bioreactors
OT  - niche separation
OT  - nitrification
OT  - nitrite oxidation
OT  - nitrite-oxidizing bacteria
OT  - physiology
OT  - qPCR
EDAT- 2019/03/03 06:00
MHDA- 2020/04/10 06:00
PMCR- 2019/10/18
CRDT- 2019/03/03 06:00
PHST- 2018/10/25 00:00 [received]
PHST- 2019/02/07 00:00 [accepted]
PHST- 2019/03/03 06:00 [pubmed]
PHST- 2020/04/10 06:00 [medline]
PHST- 2019/03/03 06:00 [entrez]
PHST- 2019/10/18 00:00 [pmc-release]
AID - AEM.02569-18 [pii]
AID - 02569-18 [pii]
AID - 10.1128/AEM.02569-18 [doi]
PST - epublish
SO  - Appl Environ Microbiol. 2019 Apr 18;85(9):e02569-18. doi: 10.1128/AEM.02569-18. 
      Print 2019 May 1.