title: Archaea and Bacteria Acclimate to High Total Ammonia in a Methanogenic Reactor Treating Swine Waste.
abstract: Inhibition by ammonium at concentrations above 1000 mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H2accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH3-N) from 890 ± 295 to 2040 ± 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophicMethanoculleus(36.4%) andMethanobrevibacter(11.6%), along with acetoclasticMethanosaeta(29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers (Clostridium,Coprococcus, andSphaerochaeta) and syntrophic fatty-acid Bacteria (Syntrophomonas,Clostridium, Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than ~1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of ~2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis.
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
authors.forename: Sofia
authors.identifier: 0000-0001-8946-9654
authors.initials: S
authors.lastname: Esquivel-Elizondo
authors.affiliation: Department of Civil Engineering, Kansas State University, 2118 Fiedler Hall, Manhattan, KS 66506, USA.
authors.forename: Prathap
authors.initials: P
authors.lastname: Parameswaran
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA.
authors.forename: Anca G
authors.identifier: 0000-0002-9354-0246
authors.initials: AG
authors.lastname: Delgado
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA.
authors.forename: Juan
authors.identifier: 0000-0002-2322-9620
authors.initials: J
authors.lastname: Maldonado
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Rittmann
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
authors.forename: Rosa
authors.identifier: 0000-0001-6064-3524
authors.initials: R
authors.lastname: Krajmalnik-Brown
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis; D000818:Animals; D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D058448:Biota; D003470:Culture Media / Q000737:chemistry; D008372:Manure; D060888:Real-Time Polymerase Chain Reaction; D013552:Swine
chemical_list: D003470:Culture Media; D008372:Manure; D000641:Ammonia