The aim of this research was to investigate the short- and long-term effects of thermosonication and different physicochemical properties of wine on culturability, viability, and metabolic activity of Brettanomyces bruxellensis yeast. Thermosonication was conducted at 43 °C during 1, 2, and 3 min, while wine variations included several pH, alcohol, and sugar levels. Cell culturability and viability were determined immediately after treatment and during 90 days of storage, while metabolic activity was determined after 90 days of storage. Results showed that, although culturability was not confirmed in dry wines immediately after 3 min of treatment, thermosonication did not result in complete inactivation of the B. bruxellensis population. Herein, the first evidence of a viable but not culturable (VBNC) state of B. bruxellensis after thermosonication exposure was observed. Moreover, thermosonication reduced the production of volatile phenols. Obtained results suggest application of thermosonication for reduction of the B. bruxellensis population only in early stages of wine contamination.
Keywords: Brettanomyces bruxellensis; red wine; thermosonication; viable but not culturable (VBNC) state; volatile phenols.