Exopolymeric substance from Bacillus velezensis P1 as an antifungal additive in chitosan coating to prolong the shelf life of mangoes.

Bacillus velezensis P1 inhibits various phytopathogenic fungi. Its exopolymeric substance (EPS) was active against Colletotrichum sp. at a minimum inhibitory concentration (MIC) of 6.25 mg/ml. EPS was added to chitosan from squid pen to produce an antifungal film coating. The addition of EPS at its MIC had no effect on the color of the chitosan film. Two components showed good compatibility and the tensile strength of the film was higher than that of neat chitosan film. Mangoes were treated with six different coatings, including the two films. Fruits coated with the films showed the lowest weight loss and prolonged shelf life of mangoes to three times the shelf life of controls (water and 2 % citric acid, w/v) and completely inhibited fungal infection. Film coatings of chitosan, alone or combined with the EPS from B. velezensis P1, showed potential to prolong the shelf life of ripe mangoes and decrease postharvest losses.