高压热杀菌结合葡萄糖对枯草芽孢杆菌芽孢的杀灭效果

Effects of High Pressure Thermal Sterilization Combining with Glucose on the Sterilization of Bacillus subtilis

作者研究了葡萄糖结合高压热杀菌(HPTS)处理对枯草芽孢杆菌芽孢的杀灭效果及其内膜的影响,通过平板计数法、电导率测定、流式细胞术分析及傅里叶变换红外光谱分析等对枯草芽孢杆菌芽孢的灭菌效果、离子释放量、内膜通透性及膜结构稳定性进行了研究。结果表明:在600 MPa、75℃条件下,芽孢死亡量达到4.64个对数值,而在添加了质量分数60%的葡萄糖溶液后,芽孢的死亡量减少了约2个对数值。随着葡萄糖质量分数的升高,芽孢的离子释放量显著下降(P<0.05);流式细胞术结果显示在600 MPa、75℃结合质量分数60%葡萄糖溶液处理下样品的阳性区域(M2)占比为92.88%,这表明芽孢内膜通透性显著增加(P<0.05);通过分析样品在3000~2800 cm-1波段的傅里叶变换红外光谱,发现与单独HPTS处理相比,添加葡萄糖可以使芽孢内膜的—CH2/—CH3官能团吸收峰明显减弱,葡萄糖可有助于维持芽孢内膜结构的稳定性。由此可知,葡萄糖质量分数对HPTS灭活枯草芽孢杆菌芽孢的效果有重要影响。

The effects of high pressure thermal sterilization(HPTS)combined with glucose on the sterilization effect and the impact on the inner membrane of Bacillus subtilis spores were investigated.The sterilization effect,ion release,intimal permeability,and membrane structure stability of Bacillus subtilis spores were studied through plate counting,conductivity measurement,flow cytometry analysis,and Fourier transform infrared spectroscopy analysis.The results showed that the lg value of inactivation rate of spores reached 4.64 with HPTS treatment of 600 MPa and 75℃,while the addition of 60%mass fraction glucose reduced the lg value of inactivation rate of spores by 2.As the mass concentration of glucose increased,the ion release of spores decreased significantly(P<0.05).The result of flow cytometry showed that the proportion of the positive region(M2)in the sample under 600 MPa and 75℃with 60%mass fraction glucose treatment was 92.88%,indicating a significant increase in the intimal permeability of spores(P<0.05).By analysis of infrared spectroscopy in the 3000~2800 cm-1 band,it was found that compared to the HPTS treatment alone,HPTS combining with glucose resulted in a significant reduction in the absorption peak intensity of the characteristic functional group—CH2/—CH3 in the inner membrane of spores.Glucose contributed to the stability of inner membrane structure of spores.Therefore,the mass concentration of glucose has an important influence on the inactivation effects of HPTS on Bacillus subtilis spores.