Bacteria, acetic acid location

The relationship of the acid and methane phases to the scheme in Fig. 12.1 raises several interesting questions, such as where the acetogenic bacteria are located and whether methane is formed exclusively from acetate or from both carbon dioxide reduction and acetate in the methane-phase reactor. The experimental data useful in answering these questions include the observations that for a glucose-fed, two-phase digestion system, more than 96% of the products from the acid-phase reactor were carbon dioxide, hydrogen, acetate. 

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