1
$\begingroup$

Is the citric acid cycle aerobic or anaerobic? I know that the oxygen is required to accept the NADH electrons so that NAD+ could be regenerated. Nevertheless, if other electron acceptors, as nitrate (NO3), are present, could they also be used to regenerate the NAD+? I am asking this because I read a thesis claiming that “acetly-CoA enters the citric acid cycle and through anaerobic nitrate-respiration a multiple amount of ATP is generated.” If you have some literature that you can share with me I would be really grateful. Thanks.

$\endgroup$
  • $\begingroup$ I have changed your title because it is misleading. Strictly speaking the chemical reactions of the TCA cycle are anaerobic because oxygen is not involved in any of them. But that is not your question. Your question is about electron acceptors for NADH produced in the TCA cycle. I have kept the question in the body of the text for you to modify if you like. $\endgroup$ – David Jan 19 '18 at 16:59
1
$\begingroup$

Yes, many microbes can use electron acceptors other than oxygen.

https://en.wikipedia.org/wiki/Anaerobic_respiration

https://www.sciencedirect.com/science/article/pii/S0168165611000289

$\endgroup$
  • $\begingroup$ As it stands this is not the sort of answer this site encourages. See the Help especially the section "Provide context for links". Your answer would be improved by (1) Emphasising that the TCA is intrinsically anaerobic, it is the process of reoxidising NADH that can involve oxygen or not, (2) That for all organisms have a single electron acceptor, in most cases (and in all animals) oxygen. At the moment your answer could be interpreted as certain microbes having a choice of electron acceptor. $\endgroup$ – David Jan 19 '18 at 17:06
  • $\begingroup$ @David is that not true? $\endgroup$ – Victor Chubukov Jan 19 '18 at 18:23
  • $\begingroup$ Not that I was aware. I thought they were highly specialized, but I may be wrong. The point is to address this important question clearly in your answer, citing an example if I am wrong. $\endgroup$ – David Jan 19 '18 at 18:55
  • $\begingroup$ The redox potential of other oxidizing pairs differs from that of oxygen and water and therefore a different set of reactions must be used to obtain energy (pump protons) from oxidizing NADH with them.I am not a microbiologist, but it appears from this that, as I would have expected, most bacteria that employ other electron acceptors are obligate anaerobes and will not therefore operate alternative modes of respiration. But some facultative anaerobes appear able to do this. $\endgroup$ – David Jan 20 '18 at 14:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.