以芽孢致死率为评价指标,通过单因素和正交试验考察溶菌酶添加量、压力、温度和时间在高压CO2处理过程中对酸土脂环酸杆菌芽孢致死效果的影响,并优化杀菌条件。结果显示:溶菌酶添加量、压力和温度对芽孢致死效果的影响均显著(P〈0.05),在溶菌酶添加量0.10g/kg、压力25MPa、温度55℃、时间60min的优化条件下芽孢致死率可达到5.47个数量级。另对此条件下处理后的样品进行高效液相色谱(HPLC)和扫描电子显微镜(SEM)检测,结果显示:芽孢核心物质2,6-吡啶二羧酸(DPA)发生大量泄露,且部分芽孢完全破裂,溶菌酶对高压CO2杀灭芽孢的协同效果显著(P〈0.05)。
One-factor-at-a-time and orthogonal array design methods were used to optimize four treatment conditions including lysozyme dose,pressure,temperature and treatment time that influence the bactericidal activity(evaluated by death rate of spores) of lysozyme in coordination with high pressure carbon dioxide against Alicyclobacillus acidoterrestris spores.The results showed that lysozyme dose,pressure and temperature had a significant effect on the inactivation of Alicyclobacillus acidoterrestris spores(P 0.05).The death rate of Alicyclobacillus acidoterrestris spores reached 5.47 orders of magnitude under the optimized conditions: lysozyme dose 0.10 g/kg,pressure 25 MPa,temperature 55 ℃ and treatment time 60 min.The HPLC analysis and observation under scanning electron microscopy(SEM) of Alicyclobacillus acidoterrestris spores treated under these conditions indicated large amounts of 2,6-pyridine dicarboxylic acid(DPA) leakage and complete rupture of partial spores.In conclusion,lysozyme has a significantly synergistic effect on the inactivation of Alicyclobacillus acidoterrestris spores by high pressure carbon dioxide(P 0.05).