Inactivation of Saccharomyces cerevisiae by ultrasonic irradiation

Abstract

We have investigated the inactivation of Saccharomyces cerevisiae (yeast cells) by ultrasonic irradiation. The amplitude on the vibration face contacting the sample solution was used as an indication of the ultrasonic power intensity. The effects of the amplitude on the vibration face and the initial cell numbers on the sonolytic inactivation of yeast cells have been investigated using a horn-type sonicator (27.5 kHz). The inactivation of the yeast cells by ultrasonic irradiation shows pseudo first-order behavior. The inactivation rate constant varied from 0.0007 to 0.145 s(-1) when the amplitude on the vibration face was in the range of 1-7 microm(p-p). The change in the inactivation rate constant as a function of the amplitude on the vibration face was similar to that of the OH radical formation rate under the same conditions. The threshold of this sonicator was 3 microm(p-p) with the amplitude on the vibration face. The initial cell numbers (from 10(2) to 10(5) mL(-1)) had an influence on the inactivation of the yeast cells by ultrasonic irradiation. The inactivation rate constants varied from 0.023 to 6.4 x 10(-3) s(-1), and the inactivation by ultrasonic irradiation was fastest at the lowest initial cell numbers. In a squeeze-film-type sonicator (26.6 kHz), 90% inactivation of the yeast cells was achieved by ultrasonic irradiation for 60 min.

Comparative real-time analysis of Saccharomyces cerevisiae cell viability, injury and death induced by ultrasound (20kHz) and heat for the application of hurdle technology

“…Microbicidal/static effects associated with cavitation are thought to result predominantly from external mechanical shear forces in a liquid continuum that damage microbial cells in suspension, as well as from cavitation occurring within the cell itself (Ciccolini et al, 1997;Hughes & Nyborg, 1962). The chemical effects of cavitation-induced free radicals in aqueous solution are thought not to be microbicidal (Furuta et al, 2004;Tsukamoto et al, 2004b).…”

Study of butter fat content in milk on the inactivation of Listeria innocua ATCC 51742 by thermo-sonication

“…Several studies have also reported the use of ultrasound for microbial inactivation in other media. Some of the tested microorganisms are Saccharomyces cerevisiae (Guerrero, Tognon, & Alzamora, 2005;Tsukamoto, Constantinoiu, Furuta, Nishimura & Maeda, 2004a;Tsukamoto et al, 2004b;Guerrero, López-Malo, & Alzamora, 2001); Escherichia coli (Ugarte-Romero, Feng, Martin, Cadwallader, & Robinson, 2006;Ananta, Voigt, Zenker, Heinz, & Knorr, 2005;Furuta et al, 2004); L. monocytogenes (Mañas, Pagán, & Raso, 2000;Pagán, Mañas, Alvarez, & Condón, 1999); Salmonella (Cabeza, Ordóñez, Cambero, De la Hoz, & García, 2004); Lactobacillus rhamnosus (Ananta et al, 2005); Yersinia enterocolitica (Raso, Pagán, Condón, & Sala, 1998), among others.…”

High power ultrasonics as a novel tool offering new opportunities for managing wine microbiology

“…The kinetics of microbial inactivation are first order or pseudo first order Tsukamoto et al 2004;Zhang et al 2006) with (Guerrero et al 2001;Furuta et al 2004;Tsukamoto et al 2004) and frequency (Borthwick et al 2005). Tsukamoto et al (2004) showed that the rate of inactivation of Saccharomyces cerevisiae yeast cells by ultrasonic irradiation was a function of the amplitude of the ultrasonic wave and the initial cell numbers and was highest at higher amplitudes and lower initial cell numbers.…”

“…Tsukamoto et al (2004) showed that the rate of inactivation of Saccharomyces cerevisiae yeast cells by ultrasonic irradiation was a function of the amplitude of the ultrasonic wave and the initial cell numbers and was highest at higher amplitudes and lower initial cell numbers. Subsequently, Borthwick et al (2005) reported that yeast cell disruption was greater in a novel compact 267 kHz sonicator than in a lower frequency 20 kHz probe sonicator at the same exposure time.…”