Antifungal activity of chitosan-silver nanoparticle composite against Colletotrichum gloeosporioides associated with mango anthracnose

Abstract

Chitosan loaded with various metal ions such as Ag + , Cu 2+ , Zn 2+ , Mn 2+ and Fe 2+ has been reported to exert strong antimicrobial activity. In this study, the silver-nanoparticles (AgNPs) were synthesized at 95°C using chitosan as the reducing agent and stabilizer. The UV-Vis spectrum displayed peak in a range between 415-420 nm, the characteristic surface plasmon resonance band of silver nanoparticles. The size, shape and aggregation properties of the resultant nanoparticles were examined using field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The measurement results indicated that the chitosan-silver nanoparticle (chitosan-AgNP) composite having the mean hydrodynamic diameter range of 495-616 nm were apparently smooth and the silver nanoparticles with the size distribution was from 10 to 15 nm. Chitosan-AgNP composites had a zeta potential of +50.08 mV to +87.75 mV. In vitro conidial germination assay indicated that chitosan-AgNP composite exhibited significantly higher antifungal activity against Colletotrichum gloeosporioides than its components at their respective concentrations. In vivo assay using detached mango fruit cv. Alphonso showed that anthracnose was significantly inhibited by chitosan-AgNP composite. Therefore, this study suggests that postharvest decay in mango can be minimized by chitosan-AgNP composites and its application on a commercial scale needs to be exploited.

Prospects of Nanotechnology in Improving the Productivity and Quality of Horticultural Crops

“…For example, A-Ag NPs improve the shelf-life of lime (Citrus aurantifolium) and apple (Malus domestica) [113]. Another study conducted by Chowdappa [114] noted that chitosan-based Ag-NPs composites greatly minimize post-harvest losses in fresh mangoes and also boost quality because of their anti-fungal properties. Kumar et al [115] observed that Ag-NPs, along with biocompatible coating materials such as chitosan and glycol, improved the storage duration of red grapes up to 14 days.…”

Antifungal Properties of Pure Silver Films with Nanoparticles Induced by Pulsed-Laser Dewetting Process

“…Ag NPs show a particularly strong bactericidal performance: with silver additions, the textile has antimicrobial activities, while thin films coated on the substrate have an antifungal function. Chowdappa [10] reported that chitosan-AgNP composite exhibits a higher antifungal activity against C. gloeosporioides than its components [11]. The biological activity of metallic glass materials has also attracted significant attention in recent years [12,13].…”