Jesús Garcia-Gil garciagil at morgat.udg.es
Tue May 5 08:19:27 EST 1998


The use organic substances as electron acceptors may be a good way of
defining fermentative. However definitions in metabolism never are sharp
and clearcut. I would add a couple of statements:

1. The organic substance involved must be internal, that is, coming from
an oxidative metabolic pathway and 

2. It is widely accepted that in fermentation no cytocroms or electron
transport systems are involved. 

Remember that there ar some bacteria that undergo respiration using
external fumarate as terminal elctron acceptor to produce succinate.

Thomas Tomzynski wrote:
> A definition that I use and is supported by a microbiology professor I
> know is "the use of an organic compound as an terminal electron
> acceptor."  Since some strict anaerobes will ferment, I'd say the terms
> are non-interchangeable.  Also, I'm not positive without cracking a
> book, but I'd guess that nitrate respiration in the absence of air would
> allow an aerobe to be a facultative anaerobe but not necessarily a
> fermenter.  Does this sound OK?
> Tom
> P.S.  Of course this has nothing to do with industrial "fermentation."
> Erwinia wrote:
> <I've always had this a understanding of this term. Can someone define
> <it
> <for me and can it be interchanged with the term facultative anaerobic?


Jesús Garcia-Gil
Secció de Microbiologia        Tel: +34 72 418175
Institut d'Ecologia Aquàtica   Fax: +34 72 418150
Universitat de Girona
Campus de Montilivi
E-17071 Girona (Spain)         http://morgat.udg.es/personal/jgg.html

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