氯灭活地下水源中3种优势真菌的效能与机制

地下水源中真菌大量繁殖会产生嗅味,引发毒性反应以及产生大量肉眼可见的絮状物,严重影响供水水质.以地下水源中3种优势真菌木霉属、青霉属、枝孢属为研究对象,以氯为消毒剂,通过研究真菌孢子胞内物质泄漏,胞外三磷酸腺苷(ATP),脱氧核糖核酸(DNA)和蛋白质增加及孢子形态变化,探明了氯灭活3种真菌孢子的效能与机制.结果表明,氯灭活真菌孢子符合一级动力学,满足Chick模型,3种真菌的耐氯性为:木霉属青霉属枝孢属,真菌孢子尺寸越大,亲水性越强,灭活效果越好.氯灭活后,胞内物质泄漏,胞外特征物质(ATP、DNA、蛋白质)显著增加;氯对细胞表面破坏严重,灭活后真菌孢子凹陷,表面褶皱.综上所述,氯首先作用于孢子表面,降低孢子的可培养性,进一步作用使细胞的通透性屏障受损,导致胞内特征物质释放,以致孢子死亡.

Inactivation Efficiency and Mechanism of Three Dominant Fungal Spores in Drinking Groundwater by Chlorine

The outbreak of fungi in drinking groundwater sources can produce odor, cause toxicity and form lots of visible flocs, which seriously affect the drinking water quality. In this study, the inactivation efficiency of three dominant fungal spores Trichoderma, Penicillium, Cladosporium by chlorine was conducted, and the inactivation mechanism was explored by monitoring the hydrophobicity, the leakage of intracellular substances, the increase of extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA) and proteins, and the change of spores'' morphology. The results showed that the inactivation of fungal spores was consistent with first-order kinetics and satisfied the Chick model. The resistance to chlorine was in sequence of Trichoderma > Penicillium > Cladosporium, the larger size the fungal spores and the more hydrophilicity the fungal spores, the higher the inactivation efficiency. Chlorination resulted in the remarkable leakage of intracellular compounds, the increase of extracellular characteristic compounds (ATP, DNA and protein), the damage of the cell surface, and the fungal spores recessed and wrinkled. In summary, chlorine firstly reacted with spores'' surface and reduced their cultivability, and then resulted in the damage to the permeability barrier of the spores and the release of intracellular characteristic compounds, and finally the viability of spores was damaged.