title: Fatty acid metabolism and population dynamics in a wet biowaste digester during re-start after revision.
abstract: Volatile fatty acid (VFA) metabolism and population changes during re-start of a wet anaerobic digester for treatment of biowaste suspensions were investigated. Initially acetate and propionate accumulated. However, VFA degradation rates improved within 2 weeks, reaching a balanced metabolism with constantly low VFA concentrations. The total microbial population consisted of 60% acidogenic+acetogenic and 40% methanogenic bacteria. Maximally 5.1% of all bacteria in the digester were propionate-oxidizing bacteria. Pelotomaculum species were dominant, followed by much lower numbers of Smithella species and Syntrophobacter species. Pelotomaculum and Smithella spec. decreased during acetate and propionate accumulation and recovered later on, whereas Syntrophobacter spec. was steadily increasing during start-up. A nearly constant proportion of Methanosaeta spec. was present all time, while Methanosarcina spec. decreased and Methanomicrobiales increased during accumulation and degradation of acetate and propionate. During steady state proportions as in the inoculum were obtained.
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Biology for Engineers and Biotechnology of Wastewater, Am Fasanengarten, D-76128 Karlsruhe, Germany. Electronic address: Christoph.Moertelmaier@kit.edu.
authors.forename: Christoph
authors.initials: C
authors.lastname: Moertelmaier
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Biology for Engineers and Biotechnology of Wastewater, Am Fasanengarten, D-76128 Karlsruhe, Germany. Electronic address: Chaoran.Li3@kit.edu.
authors.forename: Chaoran
authors.initials: C
authors.lastname: Li
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Biology for Engineers and Biotechnology of Wastewater, Am Fasanengarten, D-76128 Karlsruhe, Germany. Electronic address: Josef.Winter@kit.edu.
authors.forename: Josef
authors.initials: J
authors.lastname: Winter
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Biology for Engineers and Biotechnology of Wastewater, Am Fasanengarten, D-76128 Karlsruhe, Germany; University of Applied Science, Hochschule Emden/Leer, Faculty of Technology, Division Microbiology-Biotechnology, Constantiaplatz 4, D-26723 Emden, Germany. Electronic address: Claudia.Gallert@HS-Emden-Leer.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gallert
mesh_terms: D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D056804:Biofuels; D019149:Bioreactors; D005227:Fatty Acids / Q000378:metabolism*; D018505:Waste Management / Q000379:methods*
chemical_list: D056804:Biofuels; D005227:Fatty Acids
keywords: Biowaste; Population dynamics; Start-up phase; VFA degradation; Wet digestion