The proceeds from the anaerobic digestion are carried out
in four stages [2]. These are the following steps:
1) Hydrolysis: macromolecules are cut gradually soluble
monomers by extracellular enzymes (cellulases,
hydrolases, amylases, etc. ...).
2) Acidogenesis: monomers derived from the hydrolysis step,
are converted to organic acids and alcohols with a release
ammonium (NH4
+
), carbon dioxide (CO2) and hydrogen