archaea methanogens
TRANSCRIPT
![Page 1: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/1.jpg)
Archaea
![Page 2: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/2.jpg)
![Page 3: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/3.jpg)
![Page 4: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/4.jpg)
Gram Staining Archaea(Not for the same reasons as Bacteria.)
* Gram+ cell wall like with Gram+ Bacteria, but different biochemical composition that peptidoglycan.
* Gram– due to glycoprotein surface layer not an outer membrane.
* Some with NO cell wall!
+ -
![Page 5: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/5.jpg)
Pseudomurein(Murein = NAG-NAM of peptidoglycan in Bacteria)
* Insensitive to penicillin.* NAM replaced by NAT* Unique side-chain peptide cross-links.
![Page 6: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/6.jpg)
Lipid Differences:
* Hydrocarbons not fatty acids
* Ether linked to glycerol not ester linked
![Page 7: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/7.jpg)
Two leaves (bilayer) of C20 diethers
Single layer of rigid C40 tetraethers
Which is most likely that for an extreme thermophile?
![Page 8: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/8.jpg)
Unique Means of
Autotrophy* No Calvin Cycle
* Reversed Modified TCA Cycle
* Reductive Acetyl-CoA
![Page 9: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/9.jpg)
Methanogens
![Page 10: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/10.jpg)
MethanogensObligate anaerobes dependent on fermentation bacteria.
Chemoheterotrophic: AcetoclasticAcetate to CO2 and methane
Chemoautotrophic: H2 or formate as energy & electron sourceCO2 to methane and other cellular
components
![Page 11: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/11.jpg)
![Page 12: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/12.jpg)
Methanogenesis Pathway
MCR protein is a 3 component complex; Component C is made of 3 polypeptide subunits (α,β,γ) encoded on mcrA, mcrB, and mcrG genes.
![Page 13: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/13.jpg)
Methanogen Habitats
![Page 14: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/14.jpg)
Aerobic respiration yields greatest energy due to very positive O2 redox potential.
Without O2, anaerobic respiration uses alternate terminal electron acceptors in the order of decreasing redox potential.
E = -240 mV
Methanogenesis
E = +820 mV
E = +420 mV
E = -200 mV
![Page 15: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/15.jpg)
Anearobic Complex Organic
Matter Degradation
1) Hydrolysis
2) Fermentation
3) Acetogenesis
4) Sulfate Reduction
5) Methanogenesis
![Page 16: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/16.jpg)
Carbon Cycle
Methylotrophy
![Page 17: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/17.jpg)
Methane Production - Consumption
![Page 18: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/18.jpg)
Subsurface Methane Production:
Methanogens (shallower)(12C reacts faster than 13C)
Geothermal (deeper)
![Page 19: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/19.jpg)
Sewage Treatment Plants
![Page 20: Archaea methanogens](https://reader033.vdocument.in/reader033/viewer/2022042607/55a6653a1a28abda1b8b46c3/html5/thumbnails/20.jpg)
Global ImportancePotent Greenhouse Gas
• Over 30x more potent than carbon dioxide.• Increasing emissions by 1% per year.• Increased by more nitrogen and carbon dioxide.• Primary culprits:
– Wetlands (N)– Termites (N)– Fossil Fuel (MM)– Rice paddies (MM)– Wastes (MM)– Rumen and Enteric (N/MM)– Deforestation Burning (MM)