Inactivation of bacteria and yeast using high-frequency ultrasound treatment
Inactivation of bacteria and yeast using high-frequency ultrasound treatment
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DOI：
10.1016/j.watres.2014.04.038
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发表时间：
2014-09-01
期刊：
影响因子：
12.8
通讯作者：
Lewis, Gillian D.
中科院分区：
文献类型：
--
作者：
Gao, Shengpu;Hemar, Yacine;Lewis, Gillian D.
在受控温度条件下，利用高频(850 KHz)超声波对不同生长阶段的细菌和酵母进行灭活。研究对象包括产气肠杆菌、枯草芽孢杆菌和表皮葡萄球菌三种细菌以及一种酵母菌--出芽短梗霉。研究表明，高频超声波对对数生长期和稳定期细菌均有较高的灭活效果，灭活率均在99%以上。透射电子显微镜观察表明，细菌灭活的机理主要是由于声空化产生的自由基和过氧化氢。杆状枯草杆菌也被发现对声空化的机械效应很敏感。研究表明，即使在超声波处理后，由于声空化过程中产生的过氧化氢的存在，钝化过程仍在继续。与细菌相比，出芽短梗霉对高频超声波的抵抗力更强。(C)2014爱思唯尔有限公司。保留所有权利。
High-frequency (850 kHz) ultrasound was used to inactivate bacteria and yeast at different growth phases under controlled temperature conditions. Three species of bacteria, Enterobacter aerogenes, Bacillus subtilis and Staphylococcus epidermidis as well as a yeast, Aureobasidium pullulans were considered. The study shows that high-frequency ultrasound is highly efficient in inactivating the bacteria in both their exponential and stationary growth phases, and inactivation rates of more than 99% were achieved. TEM observation suggests that the mechanism of bacteria inactivation is mainly due to acoustic cavitation generated free radicals and H2O2. The rod-shaped bacterium B. subtilis was also found to be sensitive to the mechanical effects of acoustic cavitation. The study showed that the inactivation process continued even after ultrasonic processing cessed due to the presence of H2O2, generated during acoustic cavitation. Compared to bacteria, the yeast A. pullulans was found to be more resistant to high-frequency ultrasound treatment. (C) 2014 Elsevier Ltd. All rights reserved.