In vitro antagonistic effect of Bacillus licheniformis D7 against Colletotrichum siamense Pathogenic to Mango

Abstract

The genus Bacillus includes endospore-producing Gram-positive bacteria, most of which are harmless to animals and plants while known for their ability to inhibit a variety of harmful bacteria and molds. Colletotrichum is one of the common causative agents of anthracnose in mangoes and other crops, causing great economic losses in agriculture. In order to provide a potential and eco-friendly solution for the control of the disease caused by Colletotrichum siamense, antifungal characteristics of B. licheniformis D7 culture were investigated. The results showed that B. licheniformis D7 culture contained extracellular enzymes such as chitinase, protease, cellulase and displayed the ability to deform and decompose the fungal mycelia. At high temperatures of 70℃-80℃ for 15 minutes, the culture showed residual antifungal activity of 44.4%-61.1% and remained at 27.8% when treated at 90℃. In addition, the activity remained more than 81% after 2 hours of incubation in a wide range of pH from 4.0 to 9.0. In the mango model, the culture of strain D7 showed high antagonistic effect against C. siamense and reduced anthracnose severity by more than 98.4%. Overally, B. licheniformis D7 can be considered as potential antifungal biocontrol agent of anthracnose caused by C. siamense in mango and other fruits, effectively contributing to the future sustainable agriculture.