TY - JOUR A1 - Rosenbaum, Florian P. A1 - Müller, Volker T1 - Energy conservation under extreme energy limitation: the role of cytochromes and quinones in acetogenic bacteria T2 - Extremophiles N2 - Acetogenic bacteria are a polyphyletic group of organisms that fix carbon dioxide under anaerobic, non-phototrophic conditions by reduction of two mol of CO2 to acetyl-CoA via the Wood–Ljungdahl pathway. This pathway also allows for lithotrophic growth with H2 as electron donor and this pathway is considered to be one of the oldest, if not the oldest metabolic pathway on Earth for CO2 reduction, since it is coupled to the synthesis of ATP. How ATP is synthesized has been an enigma for decades, but in the last decade two ferredoxin-dependent respiratory chains were discovered. Those respiratory chains comprise of a cytochrome-free, ferredoxin-dependent respiratory enzyme complex, which is either the Rnf or Ech complex. However, it was discovered already 50 years ago that some acetogens contain cytochromes and quinones, but their role had only a shadowy existence. Here, we review the literature on the characterization of cytochromes and quinones in acetogens and present a hypothesis that they may function in electron transport chains in addition to Rnf and Ech. KW - Anaerobes KW - Electron transport chain KW - Extremophiles KW - Thermophiles KW - Wood–Ljungdahl pathway Y1 - 2021 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63560 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-635600 SN - 1433-4909 N1 - Open Access funding enabled and organized by Projekt DEAL. VL - 25 SP - 413 EP - 424 PB - Springer CY - Tokyo ER -