HPTS结合Nisin对枯草杆菌芽孢的杀灭机理

Study on Inactivation Mechanism of Bacillus subtilis Spores by HPTS Combined with Nisin

摘要:

为了探究高压热杀菌技术（high-pressure thermal sterilization，HPTS）结合不同质量浓度乳酸链球菌素（Nisin）对枯草杆菌芽孢的杀灭效果和作用机理，采用平板计数法、紫外分光光度法、流式细胞术及傅里叶变换衰减全反射红外光谱法（ATR-FTIR）对处理后芽孢的存活率、核酸类物质泄漏量、内膜通透性及芽孢成分变化进行了研究。结果表明：HPTS结合Nisin后的杀灭效果高于单独的HPTS处理，在550 MPa、75 ℃结合500 mg/L Nisin条件下处理20 min后芽孢存活率下降了6.30；芽孢内膜通透性和内膜损伤增大，内容物泄漏量增加，芽孢核酸、肽聚糖、细胞壁等发生变化。HPTS结合Nisin处理可有效破坏芽孢内膜的水分子通透屏障，改变芽孢膜脂质、核酸、多糖结构，降低芽孢的抗性，影响芽孢的代谢进而灭活芽孢。为HPTS结合Nisin灭活枯草杆菌芽孢提供了理论基础，并促进了HPTS在食品加工中的应用。

Abstract:

In order to explore the inactivation mechanism of Bacillus subtilis spores by high-pressure thermal sterilization (HPTS) combined with different mass concentrations of Nisin, the spore survival rate, nucleic acids leakage, inner membrane permeability and spore composition changes after treatment were studied by plate counting, ultraviolet spectrophotometry, flow cytometry and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The results showed that the disinfectant effect of HPTS combined with Nisin was higher than that treated by HPTS alone. The spore survival rate decreased by 6.30 after 20 min under 550 MPa at 75 ℃ combined with 500 mg/L Nisin. It was found that the permeability and damage of spore inner membrane increased, and the content leakage amount increased, while spore nucleic acid, peptidoglycan, cell wall and other components changed. HPTS combined with Nisin treatment could effectively destroy the water permeability barrier of inner spore membrane, change the structure of spore membrane lipid, nucleic acid and polysaccharide, reduce the resistance of spore, affect the metabolism of spore and inactivate the spore. This study provided a theoretical basis for HPTS combined with Nisin to inactivate Bacillus subtilis spores, promoting the application of HPTS in food processing.