Vlphys 12
Vlphys 12
Vlphys 12
CHEMOLITHOTROPHS
Martin Könneke
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Conversion of inorganic
compounds for energy
conservation:
- Nitrification (oxidation of
ammonia to nitrate)
- Sulfur oxidation
- Iron oxidation
- Autotrophic bacteria
- Nitrogen fixing bacteria
Eo’ [mV]
O2/H2O +820 Aerobic respiration
O2
NO3- NO3-/N2 +751 Denitrification
MnO2 NO3-/NH4++363 Nitrate ammonification
Fe(III)
MnO2/Mn2++390 Manganese reduction
SO42-
FeOOH +150 Iron reduction
SO42-/HS- -218 Sulfate reduction
So/HS- -240 Sulfur reduktion
CO2/CH4 -244 Methanogenesis
CH4
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Lithotrophic Processes
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‘Knallgas reaction’
Hydrogen-oxidizing bacteria:
Key enzyme:
Hydrogenase
H2 2H+ + 2e-
2 H2 + O2 ! 2 H2O
Facultativ chemolithotrophes
(are also able to use organic compounds
as carbon source)
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Helicobacter pylori
Gram negative epsilonproteobacteria
Helicobacter pylori
(3 !m in length, 4-6 flagella)
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Habitats of Knallgasbacteria
Habitats:
Boundary between oxic and anoxic conditions:
-!Rhizosphere
Ralstonia eutropha
-!Marine sediments
Hydrogenovibrio marinus
-!Human gastrointestinal tract
Helicobacter pylori
-!Hydrothermal systems
Aquifex pyrophilus (Bacteria, 85˚C)
Pyrolobus spec. (Archaea, 106˚C)
5 H2 + 2 NO3- + 2 H+ ! N2 + 6 H2O
H2 + 2 Fe3+ ! 2 H+ + 2 Fe2+
4 H2 + SO42- + H+ ! HS- + 4 H2O
4 H2 + 2 CO2 ! acetate + 2 H2O + H+
4 H2 + CO2 ! CH4 + H2O
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Nitrification
Oxidation of ammonia to nitrate
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NO3-
Nitrate reduction
Denitrification
NO2-
Nitrification
NO
Nitrite
N 2O ammonification
Anammox NH2OH
N2
NH4+
Nitrogen fixation
Oxidation of ammonium
NO3-
NO2-
Nitrification
Anammox NH2OH
N2
NH4+
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Nitrification
Oxidation of ammonia to nitrate
Nitrate (+ V)
Nitrite oxidizers
Ammonia oxidizers
Ammonia (- III)
Ammonia oxidizer
z.B. Nitrosomonas europaea
Activation of ammonia
“elemental oxygen as reactant”
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•! Ammonia monooxygenase
(AMO) catalyzes
conversion of ammonia
(NH3) to hydroxylamine
(NH2OH)
•! AMO is membrane
associated and is
composed of 3 subunits
(AmoABC)
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Nitrit-Oxidierer
z.B. Nitrobacter winogradskyi
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Ammonium-oxidizing microorganisms
b FISH
Scale: 1 !m
c TEM
b SEM
Scale: 0.1 !m
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Nitrite
reduction
HNO2 CuNIR NO+H2O
2 H+ + HNO2
Out
H+
e-
NXH
HNO 2 e- pcy
I
NH3 + H2O V
4 H+ +O2 4 H+ 2 e- 2 H+
pcy
IV
4 H+
2 e- pcy
NADH Q AMO Q 2 H+ pcy
dehydrogenase ATPase
QH QH2 2 e- aa3
2
NAD+ 2 H+ 2 H+ 0.5 O2
NADH H2O
+ H+ 4 H+ III
4 H+ ADP + 4 H+ ATP
M. Klotz (unpublished) Pi
In
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Distribution of
Archaea and
Bacteria in
North Pacific
ocean water
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Acetyl-CoA!
!!Acetoacetyl-CoA!
!! !! Whole genome! !!
HCO3-!
Acetyl-CoA! 3-Hydroxybutyryl-CoA! analyses!
!!!! !!!!
Crotonyl-CoA!
Malonyl-CoA! !! !!
4-Hydroxybutyryl-CoA!
!!
3-Hydroxypropionate! !! !!
4-Hydroxybutyrate! Biochemical! !!
Propionyl-CoA!
!!!! analyses!
Succinate-semialdehyde!
HCO3-! !!!! !!!!
Succinyl-CoA!
Methylmalonyl-CoA!
!!
(Berg et al., 2007)!
-! Freshwater habitats
-! Aquaria
-! As symbionts in animals
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+ IV CO2
Formate
Oxidation
8 electrons (e-)
Formaldehyde
- IV Methan (CH4)
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Methane-oxidizing microorganisms
(Methylotrophs)
Methane-monooxigenase
NADH+H+ NAD
O2 H 2O Methanol-dehydrogenase
CHOO- OCO
H 2O
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Type I methylotrophes:
Ribulose monophosphate
pathway
Key enzyme:
Hexulose-P-synthase
No reducing power
required!
Type II methylotrophes:
Serine pathway
Key enzyme: Serine
transhydroxymethylase
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Sulfate (SO4-)
+ VI
Oxidation
Sulfite (+IV)
8 electrons (e-)
Thiosulfate (av. +II)
HS- + 2 O2 ! SO42- + H+ Sulfur (0)
2 HS- + O2 + 2 H+ ! 2 S0 + 2H2O
2 S0 + 3 O2 + 2H2O ! 2 SO42- + 4 H+
Hydrogen sulfide
S2O32- + H2O + 2 O2 ! 2 SO42- + 2 H+ - II
(H2S)
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Bacteria: Thiomicrospira
Beggiatoa
Thioploca
Thiomargerita
Thiobacillus denitrificans
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Size comparison:
Thiomargarita namibiensis - Drosophila
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Lithotrophic Processes
H 2O O2 Photosynthesis
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Reducing
power
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