Introduction
The first to describe anaerobic fermentative metabolism was Louis Pasteur, who described fermentation as ‘la vie sans l’air’. Today, three physiological groups of anaerobic microorganisms can be distinguished: (i) the anaerobic phototrophs, (ii) the anaerobic respirers such as denitrifiers, sulfate reducers, methanogens and homoacetogens, which use nitrate, sulfate and carbon dioxide, respectively, as electron acceptors in the absence of oxygen, and (iii) the fermentative organisms.
The Nature of Fermentation