Screening of Lactobacillus plantarum with broad-spectrum antifungal activity and its application in preservation of golden-red apples

Abstract

Fungal food spoilage is a common problem that leads to both great economic losses and serious health problems. This study screened the antifungal activity of 137 Lactobacillus plantarum isolates against six common food spoilage indicator fungi using an overlay method and indicator strains of the species Aspergillus flavus, Fusarium moniliforme, Penicillium expansum, Penicillium chrysogenum, Cladosporium cladosporioides, and Aspergillus niger. Among Lactobacillus plantarum isolates, strain IMAU80174 was selected as the most effective based on the results of mycelium growth inhibition by its cell-free supernatant (CFS) and tolerance to simulated gastrointestinal juices and bile. The CFS of Lactobacillus plantarum IMAU80174 showed heat and protease resistance, and it was active only in a low pH environment. The application of the CFS to golden-red apples could slow down spoilage caused by inoculation of Penicillium expansum.