欧姆加热对嗜酸耐热菌的杀灭作用研究

本实验探讨了欧姆加热对嗜酸耐热菌的杀灭作用。利用自行设计的批式欧姆加热装置,对苹果汁中嗜酸耐热菌进行处理,分析了欧姆加热的电压、pH值、时间及加热体积等对杀菌效果的影响,并利用扫描电镜观察微生物细胞壁膜结构的变化,利用电导率仪和紫外吸收分光光度计测定菌悬液的成分变化。结果表明欧姆加热可以有效的杀灭苹果汁中的嗜酸耐热菌,杀菌率随电压、加热体积的升高而增大,随pH值的降低而增大。通过环境扫描电镜可观察到嗜酸耐热菌的表面出现凹陷和破损,电导率仪和紫外吸收分光光度计测定细胞内容物的溢出,据此推测欧姆加热造成了嗜酸耐热菌的"电穿孔"。

Germicidal Effects of Ohmic Heating on Alicyclobacillus acidoterrestris in Apple Juice

To study the germicidal effects of ohmic heating on Alicyclobacillus acidoterrestris, the microbe was killed by self-made ohmic heating installation, and the survival curves of different voltages, heating time, pH values and volumes were compared and analyzed. The germicidal effects of ohmic heating on the microbe observed by environmental scanning electron microscope (ESEM) with conductometer and ultraviolet spectrophotometer to detect the leakage of the microbial intracellular contents. The results demonstrated that ohmic heating can destroy the Alicyclobacillus acidoterrestris efficiently. The germicidal effects on Alicyclobacillus acidoterrestris increase with voltage and volume increase, and also increase with pH value decrease. ESEM photographs of treated Alicyclobacillus acidoterrestris showed that crushed and destroyed microbe cells result from the ohmic heating, where as the increase of the electrical conductivity and the OD value indicate the leakage of the intracellular contents. Results showed that the mechanism of ohmic heating on Alicyclobacillus acidoterrestris cells is the electro-punctureda ction.