The effect of sugar concentration and temperature on growth and volatile phenol production by Dekkera bruxellensis in wine.
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.
Barata
André
A
Laboratório de Microbiologia, Departamento de Botânica e Engenharia Biológica, Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon, Portugal.
Pagliara
Daniela
D
Piccininno
Tiziana
T
Tarantino
Francesco
F
Ciardulli
Wilma
W
Malfeito-Ferreira
Manuel
M
Loureiro
Virgílio
V
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*
D003470:Culture Media; D010636:Phenols; D005632:Fructose; C042291:4-ethylphenol; D005947:Glucose