Underlying mechanisms of the antagonistic effects of Bifidobacterium adolescentis CCFM1108 on Penicillium expansum: Based on comparative transcriptome analysis

Abstract

Penicillium expansum is the primary postharvest pathogen that attacks fruits and vegetables and threatens human health. Bifidobacterium adolescentis CCFM1108 has been previously demonstrated to inhibit the growth of Penicillium expansum and patulin production; however, its modes of action remain unclear. RNA-seq analysis was used to investigate the underlying antifungal mechanism of metabolites produced by B. adolescents CCFM1108. The expression of genes in the control group and three treatment groups (1/2 MIC CFS, 1/4 MIC CFS, and acid treatment groups) was determined and further compared using GO and KEGG analyses. The inhibitory metabolites were found to participate in the dysfunction of the mitochondrial membrane, affecting energy metabolism, reactive oxidative species production, and patulin biosynthesis. Compared with the mixture of multiple metabolites of Bifidobacterium, the acid mixture affected gene expression in a more significant manner by inhibiting all critical genes included in the patulin biosynthetic pathway. The changes in the patulin biosynthetic were verified by qRT-PCR in the presence of acids. Collectively, the present study provides a clear perspective on the antifungal mechanism of metabolites produced by a B. adolescents strain through transcriptome analysis and suggests that acid mixtures could be potential candidates for the postharvest control of P. expansum.