title: Dynamics of yeast immobilized-cell fluidized-bed bioreactors systems in ethanol fermentation from lactose-hydrolyzed whey and whey permeate.
abstract: We studied the dynamics of ethanol production on lactose-hydrolyzed whey (LHW) and lactose-hydrolyzed whey permeate (LHWP) in batch fluidized-bed bioreactors using single and co-cultures of immobilized cells of industrial strains of Saccharomyces cerevisiae and non-industrial strains of Kluyveromyces marxianus. Although the co-culture of S. cerevisiae CAT-1 and K. marxianus CCT 4086 produced two- to fourfold the ethanol productivity of single cultures of S. cerevisiae, the single cultures of the K. marxianus CCT 4086 produced the best results in both media (Y EtOH/S = 0.47-0.49 g g(-1) and Q P = 1.39-1.68 g L(-1) h(-1), in LHW and LHWP, respectively). Ethanol production on concentrated LHWP (180 g L(-1)) reached 79.1 g L(-1), with yields of 0.46 g g(-1) for K. marxianus CCT 4086 cultures. Repeated batches of fluidized-bed bioreactor on concentrated LHWP led to increased ethanol productivity, reaching 2.8 g L(-1) h(-1).
authors.affiliation: Biotechnology and Biochemical Engineering Laboratory (BiotecLab), Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Gabardo
authors.affiliation: Biotechnology and Biochemical Engineering Laboratory (BiotecLab), Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Gabriela Feix
authors.initials: GF
authors.lastname: Pereira
authors.affiliation: Enzymology Laboratory, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Manuela P
authors.initials: MP
authors.lastname: Klein
authors.affiliation: Food Science and Technology Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Rosane
authors.initials: R
authors.lastname: Rech
authors.affiliation: Food Science and Technology Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Plinho F
authors.initials: PF
authors.lastname: Hertz
authors.affiliation: Biotechnology and Biochemical Engineering Laboratory (BiotecLab), Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil. mazayub@ufrgs.br.|Food Science and Technology Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil. mazayub@ufrgs.br.
authors.forename: Marco Antônio Záchia
authors.initials: MA
authors.lastname: Ayub
mesh_terms: D019149:Bioreactors; D018914:Cells, Immobilized / Q000166:cytology / Q000378:metabolism; D018920:Coculture Techniques; D000431:Ethanol / Q000378:metabolism*; D007716:Kluyveromyces / Q000166:cytology / Q000378:metabolism*; D007785:Lactose / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D000067796:Whey / Q000378:metabolism*
chemical_list: D000431:Ethanol; D007785:Lactose
keywords: Ethanol; Immobilized cells; Kluyveromyces marxianus; Lactose-hydrolyzed whey; Lactose-hydrolyzed whey permeate; Saccharomyces cerevisiae