Antifungal effect of volatile organic compounds produced by fruit endophytic Bacillus against Aspergillus niger under postharvest conditions

The rapid postharvest deterioration of fresh fruits is closely associated with fungal contamination,particularly by Aspergills niger, which severely compromises storage stability and market value.In this study, a fruit endophytic strain, Bacillus velezensis LY G-26, was isolated and shown toproduce volatile organic compounds (VOCs) with strong antifungal activity. VOCs significantlyinhibited 4. niger mycelial growth, spore gemination, and sporulation, and induced severemembrane disruption and mitochondrial damage.

HS-SPME-GC-MS/MS identified 2-nonanone,2,S-dimethylpyrazine, and trans-2,3-dimethylacrylic acid as the primary active VOCs, with2-nonanone exhibiting the strongest inhibition. To enable practical application in food systems,LYG-26 was encapsulated into superabsorbent polymer beads, creating a packaging-compatibleslow-release system. When incorporated into sealed storage containers, the beads continuouslyreleased VOCs and significantly reduced A. niger decay in longan, effectively extending theirpostharvest shelf life.