Effect of temperature on Brettanomyces bruxellensis: Metabolic and kinetic aspects

The effect of temperatures ranging from 15 to 35°C on a culture of Brettanomyces bruxellensis was investigated in regards to thermodynamics, metabolism, and kinetics. In this temperature range, we observed an increase in growth and production rates. The growth behavior was well represented using the Arrhenius model, and an apparent activation energy of 16.61 kcal/mol was estimated. A stuck fermentation was observed at 35°C as represented by high cell death. The carbon balance established that temperature had no effect on repartition of the glucose consumption between biomass and products. Hence, the same biomass concentration was obtained for all temperatures, except at 35°C. Moreover, using logistic and Luedeking-Piret models, we demonstrated that production rates of ethanol and acetic acid were partially growth associated. Parameters associated with growth (α_eth and α_aa) remained constant with changing temperature, whereas, parameters associated with the population (β_eth and β_aa) varied. Optimal values were obtained at 32°C for ethanol and at 25°C for acetic acid.