Energy generation coupled to azoreduction by membranous vesicles from Shewanella decolorationis S12.
Previous studies have demonstrated that Shewanella decolorationis S12 can grow on the azo compound amaranth as the sole electron acceptor. Thus, to explore the mechanism of energy generation in this metabolism, membranous vesicles (MVs) were prepared and the mechanism of energy generation investigated. The membrane, which was fragmentized during preparation, automatically formed vesicles ranging from 37.5-112.5 nm in diameter under electron micrograph observation. Energy was conserved when coupling the azoreduction by the MVs of an azo compound or Fe(III) as the sole electron acceptor with H2, formate, or lactate as the electron donor. The amaranth reduction by the vesicles was found to be inhibited by specific respiratory inhibitors, including Cu(2+) ions, dicumarol, stigmatellin, and metyrapone, indicating that the azoreduction was indeed a respiration reaction. This finding was further confirmed by the fact that the ATP synthesis was repressed by the ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD). Therefore, this study offers solid evidence of a mechanism of microbial dissimilatory azoreduction on a subcell level.
Hong
Yi-Guo
YG
South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, P. R. China. yghong@scsio.ac.cn
Guo
Jun
J
Sun
Guo-Ping
GP
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000548:Amaranth Dye / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002462:Cell Membrane / Q000648:ultrastructure; D003300:Copper / Q000494:pharmacology; D001728:Dicumarol / Q000494:pharmacology; D004024:Dicyclohexylcarbodiimide / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005290:Ferric Compounds / Q000378:metabolism; D007554:Isotopes; D008797:Metyrapone / Q000494:pharmacology; D010084:Oxidation-Reduction; D011090:Polyenes / Q000494:pharmacology; D019163:Reducing Agents / Q000378:metabolism; D020592:Shewanella / Q000378:metabolism* / Q000648:ultrastructure; D014131:Trace Elements; D014475:Uncoupling Agents / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D005290:Ferric Compounds; D007554:Isotopes; D011090:Polyenes; D019163:Reducing Agents; D014131:Trace Elements; D014475:Uncoupling Agents; D004024:Dicyclohexylcarbodiimide; D003300:Copper; D001728:Dicumarol; D000255:Adenosine Triphosphate; D000548:Amaranth Dye; C041573:stigmatellin; D008797:Metyrapone