title: The effect of sugar concentration and temperature on growth and volatile phenol production by Dekkera bruxellensis in wine.
abstract: The wine spoilage yeast Dekkera bruxellensis was evaluated for the production of 4-ethylphenol under low concentrations (0.02-20 g L(-1)) of glucose and fructose in synthetic media. Measurable amounts of 4-ethylphenol were produced over 0.2 g L(-1) of each sugar. The yeast growth rate and amount of biomass formed increased from 0.2 to 20 g L(-1) of glucose or fructose, being accompanied by increasing production of 4-ethylphenol. In red wines, the production of 4-ethylphenol was only observed in the presence of growing populations of indigenous or inoculated strains of D. bruxellensis. The production rate of 4-ethylphenol varied between 22 and 93 mug day(-1) either with inoculated strains or wild populations in bottled wines. The production rate of 4-ethylphenol as a function of the increase in the number of cells varied from 349 to 1882 mug L(-1) per one log CFU mL(-1). The effect of temperature on cellular viability and 4-ethylphenol production was tested in red wines with indigenous or inoculated strains of D. bruxellensis. Incubation temperatures of 15, 20 and 25 degrees C allowed cellular growth and volatile phenol production. Increasing incubation temperatures to 36 degrees C induced full viability loss of 10 strains of D. bruxellensis within <12 h.
authors.affiliation: Laboratório de Microbiologia, Departamento de Botânica e Engenharia Biológica, Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon, Portugal.
authors.forename: André
authors.initials: A
authors.lastname: Barata
authors.forename: Daniela
authors.initials: D
authors.lastname: Pagliara
authors.forename: Tiziana
authors.initials: T
authors.lastname: Piccininno
authors.forename: Francesco
authors.initials: F
authors.lastname: Tarantino
authors.forename: Wilma
authors.initials: W
authors.lastname: Ciardulli
authors.forename: Manuel
authors.initials: M
authors.lastname: Malfeito-Ferreira
authors.forename: Virgílio
authors.initials: V
authors.lastname: Loureiro
mesh_terms: D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry*; D005516:Food Microbiology; D005632:Fructose / Q000032:analysis*; D005947:Glucose / Q000032:analysis*; D010636:Phenols / Q000378:metabolism*; D004718:Saccharomycetales / Q000254:growth & development* / Q000378:metabolism; D013696:Temperature; D014835:Volatilization; D014920:Wine / Q000382:microbiology*
chemical_list: D003470:Culture Media; D010636:Phenols; D005632:Fructose; C042291:4-ethylphenol; D005947:Glucose