title: Continuous alcoholic fermentation process in a tower reactor with recycling of flocculating yeast.
abstract: The influence of different substrate concentrations on the performance of a continuous system of alcohol production by fermentation using a tower reactor with recycling of flocculating yeasts was investigated. All experiments were carried out using a flocculating yeast strain IR-2, isolated from fermented food, and identified as Saccharomyces cerevisiae. Cane sugar juice was used as a substrate with sugar concentrations of 160, 170, 180, 190, and 200 g/L. Constant values of dilution rate, 0.20 h-1, temperature, 30 degrees C, and pH 3.3, were used. The performance of the reactor was observed to be efficient with high substrate concentrations. Maximum productivities of 18 g/L/h 99% substrate conversion and ethanol concentrations of 90 g/L were obtained using 200 g/L of sugar in the feedstock. For substrate concentrations of 160 g/L, a maximum yield of 0.45 g of ethanol/g of sugar was observed or 90% of the theoretical value.
authors.affiliation: Departamento de Biotecnologia, Faculdade de Engenharia Química de Lorena, SP, Brazil.
authors.forename: T C
authors.initials: TC
authors.lastname: Paiva
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: A E
authors.initials: AE
authors.lastname: Visconti
authors.forename: L A
authors.initials: LA
authors.lastname: Castro
mesh_terms: D001709:Biotechnology / Q000295:instrumentation*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology*; D005427:Flocculation; D007218:Industrial Microbiology / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
chemical_list: D000431:Ethanol