Sarah Douglas Shelbi Russell Ammonia oxidation NH 3 NH 2 OH NO 2 AmoABC HAO Bacteria amp Archaea Bacteria Archaeal pathway unknown hydroxylamine may be oxidized by the ID: 163759
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Slide1
Ammonia Oxidizer Enrichment
Sarah Douglas
Shelbi RussellSlide2
Ammonia oxidation
NH
3
+ NH2OH NO2-
AmoABC
HAO
Bacteria & Archaea
Bacteria
Archaeal pathway unknown,
hydroxylamine may be oxidized
by the
nitroxyl
pathway
(Walker et al., 2010)Slide3
Phylogenetic diversity of ammonia oxidizers
Bacteria
β
-Proteobacteria (Nitrosomonas &
Nitrospira) γ
-Proteobacteria (Nitrosococcus)CrenarchaeotaSlide4
Sampling
Monterey Bay Aquarium
activated
sand 19°C and 20°C
Hopkins sand by aquarium outflow and coastSlide5
Enrichment procedure
Crenarchaeota
medium inoculated with 50
mL of 10 mM filtered slurry water sample
NH4ClCofactors:7-vitamin, selenite/tungstate, and SL12 trace metal solution
Bicarbonate carbon sourcePhosphate bufferStore in the dark
Sample every 2 days for 2 weeksSlide6
Spectrophotometric determination of substrate and product concentrationSlide7Slide8Slide9
Monterey Bay Aquarium Bradley’s experiment
Added 200
uM
AmmoniaSlide10
PCR amplification of bacterial and archaeal
amoA
AOA
amoA
AOB
amoA
Monterey Bay
Aquarium sand 21°
Monterey Bay
Aquarium sand 18°
Hopkins beach sand
Hopkins aquarium sand
Positive controlSlide11
ConclusionBacterial ammonia oxidizers appear to be more prevalent
Archaea at competitive disadvantage in high ammonia environments
?
Lack of correlation between ammonia depletion and nitrite generation: complex ecosystem?