title: Effect of pH and retention time on volatile fatty acids production during mixed culture fermentation.
abstract: Mixed culture fermentation consists of stable microbial population hence waste could be potentially used as a substrates. The aim of the work was to investigate the impact of pH and retention time on the anaerobic mixed culture fermentation. Trials at different pH (4-12) in unbuffered systems were conducted for 5, 10 and 15days. The highest VFAs concentration was achieved after 15days at pH 10 (0.62g/gVSadded), promising results were also achieved for pH 11 (0.54g/gVSadded). For pH 4 and short retention time propionic acid was the major product instead of acetic acid. For batches run at 15days (besides pH 6) caproic acid presence was noticed whereas at pH 11 occurrence of succinic was quantified. Significant correlation between operational factors and fermentation's effluents was proved. Throughout changing simple operating parameters one could design process to produce desirable concentration and composition of VFAs.
authors.affiliation: Institute of Environmental Engineering, Faculty of Civil and Environmental Engineering, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Jankowska
authors.affiliation: Institute of Environmental Engineering, Faculty of Civil and Environmental Engineering, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Chwiałkowska
authors.affiliation: Department of Kinetics and Catalysis, Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznan, Poland.
authors.forename: Mikołaj
authors.initials: M
authors.lastname: Stodolny
authors.affiliation: Institute of Environmental Engineering, Faculty of Civil and Environmental Engineering, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland. Electronic address: piotr.oleskowicz-popiel@put.poznan.pl.
authors.forename: Piotr
authors.initials: P
authors.lastname: Oleskowicz-Popiel
mesh_terms: D001421:Bacteria, Anaerobic / Q000737:chemistry* / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D018920:Coculture Techniques / Q000379:methods*; D003470:Culture Media / Q000737:chemistry; D005232:Fatty Acids, Volatile / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008657:Metabolic Clearance Rate; D059013:Microbial Consortia / Q000502:physiology
chemical_list: D003470:Culture Media; D005232:Fatty Acids, Volatile
keywords: Anaerobic digestion; Mixed culture fermentation; Volatile fatty acids