Development of biocomposite films incorporated with the extract from pitcher associated bacteria for the postharvest protection from fungi

Abstract

Pythium aphanidermatum is known to cause diseases like damping-off, root rot, stem rot and fruit rot in a wide range of plants. Eventhough many chemical methods have been demonstrated to have the potential to manage these diseases, their benefits are being offset equally by the negative side effects. Therefore, the control of Pythium spp. using natural antifungal agents is of immense significance due to its environmental safety. Here, the plant associated microorganisms with antifungal metabolites have significant promises to be explored both as sustainable biocontrol agents and also as active constituents of antifungal materials. Antimicrobial packaging films prepared using such components can have significant applications to meet the requirements to prevent postharvest loss of agricultural produce by inhibiting the fungal growth. Eventhough there are reports on the development of antimicrobial packaging films for such applications, the use of bacterial extracts with antifungal activity for the same is least investigated. Hence, the present study demonstrates the development of biocomposite films prepared using polyvinyl alcohol (PVA) incorporated with the extracts prepared from bacterial isolates (Serratia sp. NhPB1, Kocuria sp. NhPB49, and Pantoea dispersa NhPB54) previously isolated from the pitcher plant. Here, the individual films were prepared by incorporating 1 mL of bacterial extract in 40 mL of 3% PVA solution and the developed films were then subjected to antifungal activity screening against P. aphanidermatum. The antifungal activity analysis of the films prepared with the incorporation of extracts from Serratia sp. NhPB1, Kocuria sp. NhPB49, and Pantoea dispersa NhPB54 showed remarkable activity against the tested pathogen. The application of biocomposite films on Solanum lycopersicum and Capsicum annuum fruits for its protection from P. aphanidermatum by dip coating method further indicates the promises of developed biocomposite films for active packaging applications.