Biocontrol of Postharvest Colletotrichum Decay in Red Chili and Tomato with Bacillus SubtilisATCC 21556

Abstract

Bacillus subtilis ATCC 21556 produces the highest an antifungal of iturin A compared to the other three of B. subtilis strains ATCC 15841, ATCC 27505, and ATCC 21770. An Iturin A has a wide antifungal spectrum activity, therefore making it an ideal potential for controlling of the fungal diseases of crop not only for preharvest but also for postharvest control. This research work if very useful to overcome the problem of decreased post-harvest production of chili and tomato that caused by the fungal pathogen. Many of the fungi cause of postharvest disease in various fruits and vegetables. Biological control of postharvest diseases has emerged as an effective alternative control since the impact of chemical control of post-harvest disease cause serious consequences for human health and the environment. Twenty microliters of B. subtilis ATCC 21556 (approximately 1 x 107 cell mL-1) were injected into the fruit of red chillies and tomatoes to control its postharvest diseases caused by fungal of Colletotrichum scovillei 244830. The lesion diameter of C. scovillei 244830 significantly (p<0.005) reduced about 52-64% in chili and 39-44% in tomato. An invitro test showed that percent growth inhibition of B. subtilis ATCC 21556 against C. scovillei 244830 was about 52.38% at 14 days of the incubation time. For successful infection of the fungal pathogens into the host plants, they produce the extracellular enzymes. Qualitative test of the extracellular enzymes showed that C. scovillei 244830 produced the enzymes of amylase, laccase, lipase, pectate lyase, and protease and it did not produce polygalacturonase.