Acidogenic Phase

Acidogenic phase Methanogenic phase Post-Methanogenic phase... 

In the acidogenic phase, acetyl-CoA and butyryl-CoA are converted to acetate and butyrate, respectively, which are reassimilated in the solvenotogic phase. The enzyme at the center of acid reassimilation and solvent production is... 

Fig. 1 Biochemical pathways of ABE fermentation in C. acetobutylicum. Reactions prevailing during the acidogenic phase of the fcmnentation are shown with dotted arrows, and reactions prevailing during the solventogenic phase are displayed by thick arrows...

The acidogenic phase typically takes place during the exponential growth phase of the culture. 

In relation to PVC additives, the study concluded that heavy metal additives are more likely to be released under acidogenic conditions (compared with plasticizers, for example, which are released mainly during the anaerobic and methanogenic phases of landfill development). With respect to landfill emissions, it was concluded that organotin compormds carmot be directly attributed to the presence of PVC in landfills. 

In sewer networks without considerable amounts of sediments, the anaerobic processes are dominated by the acidogenic production of VFA and C02 and by sulfate reduction (hydrogen sulfide production). The methanogenic phase can normally be excluded as being of minor importance. These facts were verified by Tanaka and Hvitved-Jacobsen (1999) and Tanaka (1998) under sewer conditions in a number of laboratory experiments and in the field. 

Boija, R. Martin, A. Sanchez, E. Rincon, B. Raposo, F. Kinetic modelling of the hydrolysis, acidogenic and methanogenic steps in the anaerobic digestion of two-phase olive pomace (TPOP). Process Biochem. 2000,40, 1841-1847. 

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