Sulfate-Reducing bacteria Strict anaerobes, Divided into two broad physiological subgroups: Genera in Group I(Desulfovibrio, Desulfomonas Desulfotomaculum, Desulfobulbus utilize lactate, pyruvate, ethanol, or certain fatty acids as carbon and energy sources, reducing sulfate to hydrogen sulfide Genera in Group I (Desulfococcus, Desulfosarcina Desulfonema, Desulfonema) specialize in the oxidation of fatty acids, particularly acetate, reducing sulfate to sulfide Growth and reduction of sulfate by Desulfotomaculum in certain canned foods leads to a type of spoilage called sulfide stinker, Habitants of anoxic aquatic and terrestrial environments
Sulfate-Reducing Bacteria Strict anaerobes, Divided into two broad physiological subgroups: Genera in Group I (Desulfovibrio, Desulfomonas, Desulfotomaculum, Desulfobulbus) • utilize lactate, pyruvate, ethanol, or certain fatty acids as carbon and energy sources, reducing sulfate to hydrogen sulfide Genera in Group II (Desulfococcus, Desulfosarcina, Desulfonema, Desulfonema) • specialize in the oxidation of fatty acids, particularly acetate, reducing sulfate to sulfide Growth and reduction of sulfate by Desulfotomaculum in certain canned foods leads to a type of spoilage called sulfide stinker, Habitants of anoxic aquatic and terrestrial environments
Sulfur-Reducing bacteria Able to reduce elemental sulfur to sulfide Unable to reduce sulfate to sulfide Obligate anaerobes Utilize only sulfur as an electron acceptor Also referred to as dissimilatory sulfur reducing bacteria Members of the genus Desulfuromonas can grow anaerobically by coupling the oxidation of substrates such as acetate to ethanol to the reduction of elemental sulfur to hydrogen sulfide
Sulfur-Reducing Bacteria Able to reduce elemental sulfur to sulfide Unable to reduce sulfate to sulfide Obligate anaerobes Utilize only sulfur as an electron acceptor Also referred to as dissimilatory sulfurreducing bacteria Members of the genus Desulfuromonas can grow anaerobically by coupling the oxidation of substrates such as acetate to ethanol to the reduction of elemental sulfur to hydrogen sulfide
Homoacetogenic Bacteria Obligate anaerobes Gram-positive CO2 as a terminal electron acceptor Acetate as the sole product of anaerobic respiration Acetyl-CoA pathway convert CO2 to acetate Typical species: Acetobacterium woodii and Clostridium aceticum
Homoacetogenic Bacteria Obligate anaerobes Gram-positive CO2 as a terminal electron acceptor Acetate as the sole product of anaerobic respiration Acetyl-CoA pathway convert CO2 to acetate Typical species: Acetobacterium woodii and Clostridium aceticum
Homoacetogenic Bacteria cO2 cHo-mHF→ CH:THFS-CH3 Formyl ATP THE、 Ni -Ni-CH3 -Ni co dehydrogenas CoA N Mechanism of motive force autotrophy in homoacetogenic ATP sulfate-reducing and methanogenic CH 3 C-o SCOA bacteria Acetate ATP Acetyl-COA Net: 4 H2+2 CO2- Acetate+2 H2O+H Reactions of the Acetyl-CoA Pathway
Homoacetogenic Bacteria Mechanism of autotrophy in homoacetogenic, sulfate-reducing and methanogenic bacteria Reactions of the Acetyl-CoA Pathway
Budding and Appendaged(Prosthecate) Bacteria Ancalomicrobium acetum Asticcacaulis biprosthecum Holdfast Ancalochloris perfiliewi rosthecae s stella Flagellum Swarmer cell
Budding and Appendaged (Prosthecate) Bacteria Asticcacaulis biprosthecum Ancalomicrobium adetum Ancalochloris perfilievii Stella