Study on germination-induced photocatalytic inactivation of aspergillus fumigatus and its mechanism
ZHANG Huanhuan
TIAN Bu
ZENG Bo
WU Qianling
Abstract：It is well established that the mortality rate of mold spores is typically lower than that of bacteria and viruses.This study,leveraging photocatalytic technology,elucidates the mechanism by which spore ger-mination enhances sterilization efficacy.Under visible light irradiation,a g-C3N4/Bi4O7 composite catalytic system was employed to conduct inactivation experiments on dormant spores of Aspergillus fumigatus.The results indicated that this catalytic system exhibited negligible inactivation effects on dormant spores.Howev-er,when the spores were in a germinated state,the catalytic system demonstrated highly efficient inactivation capabilities,achieving a sterilization rate of up to 81％within 6 hours.To identify the key reactive species re-sponsible for the visible light photocatalytic sterilization by the g-C3N4/Bi4O7 composite material,experiments were conducted using various radical scavengers,including ammonium oxalate,potassium dichromate,t-buta-nol,and p-benzoquinone.The findings revealed that superoxide radicals(·O2-)and hydroxyl radicals(·OH)are the predominant reactive species in the photocatalytic sterilization process.Furthermore,to inves-tigate the inactivation mechanism of germinated spores under photocatalytic action,scanning electron micros-copy and confocal microscopy were utilized to monitor the live/dead status of the germinated spores.It was observed that,as the photocatalytic reaction time increased,the reactive species clustered around the germina-ted spores continuously attacked the cell wall/membrane,causing severe damage to the surface of the fungal cells.Additionally,the results of the detection of the concentrations of K+unveiled that the massive leakage of intracellular K+is the primary cause leading to the complete inactivation of the mold.These discoveries pro-vide a clear depiction of the inactivation process of germinated spores under photocatalytic action and offer sub-stantial evidence for a deeper understanding of the underlying mechanisms.
Keywords：aspergillus fumigatusgerminationphotocatalysisK+detection
Publication Date：2025-06-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 48-55,87 )