芽孢是最难杀灭的微生物，高压热杀菌技术（HPTS）能有效杀灭芽孢，同时对食品品质的影响较小。然而，对HPTS杀灭芽孢机理的研究长期没有大的突破。HPTS会引起芽孢皮层肽聚糖支架水解，这是其造成芽孢死亡的一个关键原因，但HPTS诱发皮层肽聚糖水解的机理尚不明确。本项目以从枯草杆菌芽孢中分离的皮层裂解酶和皮层肽聚糖为切入点,对其进行HPTS处理，采用电泳法、圆二色光谱法、傅里叶变换红外光谱法、荧光光谱分析法、紫外吸收光谱扫描法、表面巯基含量测定法及原子力显微镜分别从一级、二级、高级及超微结构等不同研究层次上揭示HPTS对皮层裂解酶活性的影响。同时，采用反相高效液相色谱法、基质辅助激光解吸电离飞行时间质谱法分析皮层肽聚糖的水解产物，阐明HPTS对皮层肽聚糖支架非酶水解的作用。进而揭示HPTS导致芽孢皮层肽聚糖支架水解的机理，推进对HPTS杀灭芽孢机理的阐明，有力地推动HPTS在食品工业中的应用。

Bacterial spores are the most difficult microorganisms to be inactivated. High-pressure thermal sterilization (HPTS) can inactivate the spores and cause smaller damages on food qualities. However, there has been no major breakthrough in the study on spore inactivation mechanism by HPTS for a long time. HPTS can induce the hydrolysis of peptidoglycan support of spore's cortex, which is a critical reason for spore inactivation by HPTS. However, the hydrolysis principle of cortex peptidoglycan under HPTS is still not clarified. This project uses cortex-lytic enzymes and cortex peptidoglycan isolated from Bacillus subtilis spores as entry points, and treats the enzymes and peptidoglycan with HPTS respectively. The effects of HPTS on the activity of cortex-lytic enzymes are discovered at different research levels of primary structure, secondary structure, senior structure and ultrastructure by the methods of electrophoresis, circular dichroism spectrum, Fourier transform infrared spectroscopy, spectrofluorimetry, ultraviolet absorption spectrum scanning, measurement of surface sulfydryl content and atomic force microscope. Meanwhile, the hydrolysate of cortex peptidoglycan is analyzed by reverse-phase HPLC and matrix-assisted laser desorption ionization-time of flight MS, and the effects of HPTS on the non-enzymatic hydrolysis of cortex peptidoglycan are clarified. Finally, the hydrolysis principle of peptidoglycan support of bacterial spore's cortex under HPTS is discovered, which will improve the illumination of spore inactivation mechanism by HPTS, and impel effectively the application of HPTS in food industry.