Reduction of accumulated volatile fatty acids by an acetate-degrading enrichment culture.
The effects of the addition of an acetate-degrading enrichment culture to an anaerobic digester with a stagnating biogas production were investigated. Initially, a thermophilic batch-operated lab-scale digester was inoculated with the diluted fermenter sludge of a biogas plant, and process parameters including the concentration of volatile fatty acids (VFAs) and gases in the headspace were measured. After a phase of high gas production, a stagnation of biogas production followed for a further 30 days. An acetate enrichment culture was added 34 days after the commencement of the experiment and this resulted in a sharp decrease in the concentrations of accumulated VFAs and an increase in total biogas and CH(4) production. An archaeon with a sequence similarity of 98% to Methanosarcina sp. and the ability to degrade acetic acid was introduced with the enrichment culture and is proposed to have been the driving factor for the changes that occurred within a few days to the process.
Lins
Philipp
P
Institute of Microbiology, University of Innsbruck, Innsbruck, Austria. philipp.lins@uibk.ac.at
Malin
Cornelia
C
Wagner
Andreas Otto
AO
Illmer
Paul
P
D000085:Acetates / Q000378:metabolism*; D056804:Biofuels; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005285:Fermentation; D017020:Methanosarcina / Q000378:metabolism*; D012722:Sewage
D000085:Acetates; D056804:Biofuels; D005232:Fatty Acids, Volatile; D012722:Sewage