title: Hydrogen production from cheese whey with ethanol-type fermentation: effect of hydraulic retention time on the microbial community composition.
abstract: The effects of different hydraulic retention times (HRTs) of 4, 2, and 1h and varying sources of inoculum (sludge from swine and sludge from poultry) on the hydrogen production in two anaerobic fluidized bed reactors (AFBRs) were evaluated. Cheese whey was used as a substrate, and 5000mgCODL(-1) was applied. The highest hydrogen yield (HY) of 1.33molmol(-1) lactose and highest ethanol yield (EtOHY) of 1.22molEtOHmol(-1) lactose were obtained at the highest HRT (4h). When the reactors were operated at an HRT of 1h, methane (0.68LCH4h(-1)L(-1)) was produced concurrently with hydrogen (0.51LH2h(-1)L(-1)). The major metabolites observed were soluble ethanol, methanol, acetic acid, and butyric acid. Cloning of the 16S rRNA gene sequences indicated that the microbial community were affiliated with the genera Selenomonas sp. (69% of the sequences), and Methanobacterium sp. (98% of the sequences).
authors.affiliation: Department of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luis, km 235, CEP 13565-905 São Carlos, SP, Brazil.
authors.forename: Paula Rúbia Ferreira
authors.initials: PR
authors.lastname: Rosa
authors.affiliation: Department of Hydraulic and Sanitation, University of São Paulo, Av. Trabalhador Sãocarlense, 400, Centro, CEP 13566-590 São Carlos, SP, Brazil.
authors.forename: Samantha Christine
authors.initials: SC
authors.lastname: Santos
authors.affiliation: Department of Hydraulic and Sanitation, University of São Paulo, Av. Trabalhador Sãocarlense, 400, Centro, CEP 13566-590 São Carlos, SP, Brazil.
authors.forename: Isabel Kimiko
authors.initials: IK
authors.lastname: Sakamoto
authors.affiliation: Department of Hydraulic and Sanitation, University of São Paulo, Av. Trabalhador Sãocarlense, 400, Centro, CEP 13566-590 São Carlos, SP, Brazil.
authors.forename: Maria Bernadete Amâncio
authors.initials: MB
authors.lastname: Varesche
authors.affiliation: Department of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luis, km 235, CEP 13565-905 São Carlos, SP, Brazil. Electronic address: edsilva@ufscar.br.
authors.forename: Edson Luiz
authors.initials: EL
authors.lastname: Silva
mesh_terms: D056804:Biofuels; D019149:Bioreactors / Q000382:microbiology*; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D059013:Microbial Consortia; D008894:Milk Proteins / Q000378:metabolism*; D013997:Time Factors; D000067816:Whey Proteins
chemical_list: D056804:Biofuels; D008894:Milk Proteins; D000067816:Whey Proteins; D006859:Hydrogen
keywords: Cheese whey; Continuous anaerobic fluidized bed reactors; Lactococcus lactis; Methanobacterium sp.; Selenomonas sp.