Effect of Cold Plasma on Microbial Community in Cold Storage Room for Fruits and Vegetables

The effect of cold plasma treatment on the microbial community of air at the 0 ℃ cold storage was studied. The structure and diversity of the bacterial and fungal communities were analyzed by high-throughput sequencing technology. The microbial symbiosis network was constructed. The results showed that the total concentration of bacteria and fungi decreased from 480 CFU/m³ to 44 CFU/m³ after cold plasma cyclic treatment for 30 days. The α diversity of bacterial and fungal communities was also significantly reduced. Principal co-ordinates analysis and permutational multivariate analysis of variance showed that the bacterial community and fungal community were significantly different before and after the treatment. Before cold plasma treatment, Bacillus, Comamonas and Acetobacter were the dominant bacteria of the cold storage air, while Saccharomycopsis, Aspergillus, Thermoascus, Rasamsonia, Penicillium, Wickerhamomyces and Russula were the dominant fungi. After cold plasma treatment, Acetobacter and these dominant fungi were significantly reduced. The symbiotic network analysis showed that there was a strong positive correlation between Sedimentibacter and other bacterial species. Besides, Saccharomycopsis, Thermoascus, Rasamsonia and Wickerhamomyces were the key nodes in the fungal symbiosis network and positively correlated with each other. This work indicates that cold plasma can significantly reduce the microbial quantity and diversity of microbial community in the cold storage, and can effectively kill some phytopathogen and pathomycete, which has a good application prospect in the cold storage of fruits and vegetables.