title: Selective carboxylate production by controlling hydrogen, carbon dioxide and substrate concentrations in mixed culture fermentation.
abstract: This research demonstrated the selective production of n-butyrate from mixed culture by applying 2 bar carbon dioxide into the headspace of batch fermenters or by increasing the initial substrate concentration. The effect of increasing initial substrate concentration was investigated at 8, 13.5 and 23 g COD/L with potato processing waste stream. Within 1 week of incubation, n-butyrate fraction selectively increased up to 83% by applying 2 bar hydrogen or 78% by applying carbon dioxide into the headspace whereas it was only 59% in the control reactor. Although the fraction of n-butyrate was elevated, the concentration remained lower than in the control. Both the highest concentration and fraction of n-butyrate were observed under the highest initial substrate concentration without headspace addition. The concentration was 10 g COD/L with 73% fraction. The operational conditions obtained from batch experiments for selective n-butyrate production were validated in a continuous process.
authors.affiliation: VITO Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium. doga.arslan@vito.be
authors.forename: D
authors.initials: D
authors.lastname: Arslan
authors.forename: K J J
authors.initials: KJ
authors.lastname: Steinbusch
authors.forename: L
authors.initials: L
authors.lastname: Diels
authors.forename: H
authors.initials: H
authors.lastname: De Wever
authors.forename: H V M
authors.initials: HV
authors.lastname: Hamelers
authors.forename: C J N
authors.initials: CJ
authors.lastname: Buisman
mesh_terms: D061249:Batch Cell Culture Techniques; D057919:Biological Oxygen Demand Analysis; D002087:Butyrates / Q000378:metabolism; D002245:Carbon Dioxide / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods*; D005232:Fatty Acids, Volatile / Q000032:analysis; D005285:Fermentation / Q000187:drug effects*; D005525:Food-Processing Industry; D005947:Glucose / Q000378:metabolism; D006859:Hydrogen / Q000494:pharmacology*; D007220:Industrial Waste / Q000032:analysis; D007773:Lactates / Q000378:metabolism; D013816:Thermodynamics; D014865:Waste Disposal, Fluid; D014866:Waste Products / Q000032:analysis
chemical_list: D002087:Butyrates; D002264:Carboxylic Acids; D005232:Fatty Acids, Volatile; D007220:Industrial Waste; D007773:Lactates; D014866:Waste Products; D002245:Carbon Dioxide; D006859:Hydrogen; D005947:Glucose