Antifungal Effect of Chitosan/Nano-TiO2 Composite Coatings against Colletotrichum gloeosporioides, Cladosporium oxysporum and Penicillium steckii

Author: mycolabadmin
7/21/2021
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Summary

This research demonstrates that a coating made from chitosan combined with tiny titanium dioxide particles effectively kills three types of mold that spoil mangoes after harvest. The composite coating works by breaking down the mold’s cell membranes and causing them to leak their contents, leading to cell death. This combination is more effective than chitosan alone, with some mold species being completely eliminated at optimal concentrations.

Background

Postharvest fungal diseases caused by Colletotrichum gloeosporioides, Cladosporium oxysporum, and Penicillium steckii are major causes of mango deterioration. Chemical fungicides have been the primary control method, but long-term use has led to pathogen resistance and health concerns. Chitosan and nano-TiO2 have shown promise as antimicrobial agents, but their combined application against these specific molds requires further investigation.

Objective

To evaluate the in vitro antifungal effects of chitosan/nano-TiO2 composite coatings against three postharvest mold pathogens of mango. The study aimed to determine mortality rates, mycelial inhibition, and mechanisms of action including effects on cell membrane integrity and intracellular material leakage.

Results

The CTS/0.5% nano-TiO2 composite achieved 100% mortality and mycelial inhibition rates for C. gloeosporioides and C. oxysporum, with 75.4% mortality and 57.3% inhibition for P. steckii. The composite treatment decreased mycelial dry weight by 36.3%, increased conductivity 1.7-fold, and significantly increased protein dissolution and nucleic acid leakage compared to single chitosan treatment.

Conclusion

Chitosan/nano-TiO2 composite coatings demonstrated superior antifungal efficacy compared to chitosan alone, with effectiveness varying among the three fungal species. The composite coating appears to work by destroying cell membrane integrity, increasing permeability, and inducing intracellular material leakage, suggesting potential for development as novel antimicrobial packaging materials.

Published in:Molecules,
Study Type:In Vitro Experimental Study,
Source: 10.3390/molecules26154401, PMID: 34361552