Sugar degradation to acetate, CO2 and H2 via a novel fermentation pathway

From the postulated fermentation pathway (Fig. 14) it is probable that glucose degradation to pyruvate is not coupled with net ATP synthesis. Thus, ADP-forming acetyl-CoA synthetase appears to be the only energy-conserving site during maltose (and pyruvate) fermentation, which is in accordance with the growth yield data [294,295]. The enzyme 

Further studies indicate that an ADP-forming acetyl-CoA synthetase is also operative in other extremely thermophilic archaea Pyrococcus woesei, Thermococcus celer, Hyperthermus butylicus, Desulfurococcus amylolyticus), which form acetate as end product of their fermentation [305]. In contrast, in acetate forming (eu)bacteria, acetate formation from acetyl-CoA and the synthesis of ATP from ADP and Pj are catalyzed by two enzymes phosphate acetyltransferase and acetate kinase. This holds true for the extremely thermophilic (eu)bacterium. Thermotoga maritima[3Q5], which ferments 

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