关键词: 高压CO2, 溶菌酶, 酸土脂环酸杆菌, 芽孢致死率, 2,6-吡啶二羧酸(DPA), 扫描电子显微镜镜(SEM)

Abstract: 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).

Key words: high pressure carbon dioxide, lysozyme, Alicyclobacillus acidoterrestris, death rate of spores, 2,6-pyridine dicarboxylic acid (DPA), scanning electron microscopy (SEM)