Sterilization mechanism of CuCeO_x on fungus: Oxidative damage and energy metabolism disequilibrium

Pathogens in bioaerosols and aquatic environment cause epidemic outbreak frequently. Relative to bacteria and virus, fungi has not received attention enough. The development of sterilization materials and mechanism on fungi are limited. In this study, we proposed a non-noble metal sterilization material CuCeO_x in order to investigate its sterilization mechanism on target fungal Hanseniaspora uvarum collected from the air. The active components of CuCeO_x were uniformly distributed and induced the production of R·. The reactive oxygen species (ROS) changed from R· to RO· upon contact with fungal cells. Transcriptomics identified 1665 Differentially Expressed Genes (DEGs), including 1540 up-regulated and 125 down-regulated genes. The cell wall and external encapsulation structure were firstly damaged when the fungus contacted with CuCeO_x, and the related DEGs were significantly down-regulated. CuCeO_x could exert great impact on the energy metabolism of the cell, especially on the process of oxidative phosphorylation, which contained 59 up-regulated and 2 down-regulated genes. The cell is not sufficient to cope with the adverse environment caused by oxidative stress and metal ion homeostatic imbalance, which then modulates the intrinsic apoptotic pathway triggering apoptosis.