紫外联合过氧甲酸灭活真菌孢子的效能与机制

Efficacy and mechanism of inactivation of fungal spores by ultraviolet combined with performic acid process

探索了紫外/过氧甲酸(UV/PFA)联合工艺对两种典型致病真菌(黑曲霉和黄曲霉)的灭活效能与机制.结果显示,UV/PFA在8min时可实现黑曲霉1.21-log、黄曲霉2.08-log的灭活,且效率高于单独PFA和单独UV的效率之和,表现出协同作用.联合灭活的机制主要是UV能活化PFA生成强氧化性的羟基自由基(·OH)对细胞膜造成破坏,提高胞内活性氧水平增大细胞应激,也便于PFA渗透进入细胞内部,从而增强灭活效率.联合灭活过程中起主要作用的是UV,其次是·OH,二者在黑曲霉灭活中的贡献率分别87%和11%,在黄曲霉灭活中的贡献率分别为71%和27%.此外,经过联合灭活后,真菌再生长的时间推迟,再生长的最大潜能也得到抑制.

The inactivation efficiency and mechanism of ultraviolet/performic acid(UV/PFA)combined process against two typical pathogenic fungi(Aspergillus Niger and Aspergillus flavus)were investigated in this study.It was found that UV/PFA could inactivate 1.21-log of Aspergillus Niger spores and 2.08-log of Aspergillus flavus spores at 8min,and the inactivation efficiency of combined inactivation was higher than the sum of the inactivation efficiency of PFA and UV alone,showing a synergistic effect.The mechanism of combined inactivation was mainly that UV activated PFA to generate strong oxidizing hydroxyl radicals(•OH)to cause damage to cell membranes,increased the level of intracellular reactive oxygen species to increase cellular stress,and also facilitated the penetration of PFA into the cell interior,thus enhancing the inactivation efficiency.UV played a major role in the combined inactivation process,followed by•OH,which contributed 87%and 11%to Aspergillus Niger inactivation and 71%and 27%to Aspergillus flavus inactivation,respectively.In addition,after UV/PFA inactivation,the regeneration time of fungi was delayed and the maximum potential of regeneration growth was inhibited.