Mechanism of inhibition caused by long‐chain fatty acids in anaerobic digestion process

Acetoclastic bacteria are more affected by LCFA than hydrogenophilic bacteria.

“The acetateutilizers (acetoclastic) seem to be more aected by LCFA than the H 2 -utilizers (hydrogenophilic) bacteria (Hanaki et al., 1981).”

Hanaki et al. (1981) concluded that oleate adsorbed to the biomass within 24 h.

“Hanaki et al. (1981) concluded that oleate adsorbed to be biomass within 24 h.”

Acetoclastic bacteria are more susceptible to oleic acid than hydrogenophilic bacteria.

“which con®rms the higher susceptibility of acetoclastic bacteria to oleic acid, relative to hydrogenophilic bacteria, as reported by Hanaki et al. (1981).”

Sodium oleate was used as a model for LCFA because it is generally the most abundant LCFA in wastewater, has good solubility, is the most important LCFA produced by whole milk degradation, and is one of the more toxic LCFA.

“Sodium oleate was used as a model for LCFA because it is, in general, the most abundant of all LCFA present in wastewater (Komatsu et al., 1991), has a good solubility, it is the most important LCFA produced by whole milk degradation (Hanaki et al., 1981) and is one of the more toxic LCFA (Galbraith et al., 1971).”

Most previous works report on results from batch assays and the general conclusion is that no adaptation of methanogenic bacteria to LCFA occurs.

“Adaptation of methanogenic bacteria to LCFA is discussed in the literature, but most of the previous works report on results from batch assays (Hanaki et al., 1981;Koster and Cramer, 1987;Angelidaki and Ahring, 1992) and the general conclusion is that no adaptation of methanogenic bacteria to LCFA occurs.”