title: Bioaugmentation with an acetate-oxidising consortium as a tool to tackle ammonia inhibition of anaerobic digestion.
abstract: Ammonia is the major inhibitor of anaerobic digestion (AD) process in biogas plants. In the current study, the bioaugmentation of the ammonia tolerant SAO co-culture (i.e. Clostridium ultunense spp. nov. in association with Methanoculleus spp. strain MAB1) in a mesophilic up-flow anaerobic sludge blanket (UASB) reactor subjected to high ammonia loads was tested. The co-cultivation in fed-batch reactors of a fast-growing hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis MS2(T)) with the SAO co-culture was also investigated. Results demonstrated that bioaugmentation of SAO co-culture in a UASB reactor was not possible most likely due to the slow maximum growth rate (μmax=0.007 h(-1)) of the culture caused by the methanogenic partner. The addition of M. bourgensis to SAO led to 42% higher growth rate (μmax=0.01 h(-1)) in fed-batch reactors. This indicates that methanogens were the slowest partners of the SAO co-culture and therefore were the limiting factor during bioaugmentation in the UASB reactor.
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Ioannis A
authors.initials: IA
authors.lastname: Fotidis
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Dimitar
authors.initials: D
authors.lastname: Karakashev
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800 Kgs. Lyngby, Denmark. Electronic address: iria@env.dtu.dk.
authors.forename: Irini
authors.initials: I
authors.lastname: Angelidaki
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000641:Ammonia / Q000737:chemistry*; D000693:Anaerobiosis; D056804:Biofuels; D019149:Bioreactors / Q000382:microbiology; D003013:Clostridium / Q000378:metabolism; D018920:Coculture Techniques; D006859:Hydrogen / Q000737:chemistry; D017404:In Situ Hybridization, Fluorescence; D008697:Methane / Q000737:chemistry; D019638:Methanomicrobiaceae / Q000378:metabolism; D018613:Microscopy, Confocal; D010100:Oxygen / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors
chemical_list: D000085:Acetates; D056804:Biofuels; D012722:Sewage; D000641:Ammonia; D006859:Hydrogen; D008697:Methane; D010100:Oxygen
keywords: Ammonia inhibition; Biomethanation; Syntrophic acetate oxidation; UASB reactor