Investigating the Effect of bacillus subtilis ‘s metabolites on Penicillium Digitatum

Background and Objectives: The gram-positive bacteria, bacillus subtilis , which exist in the soil and digestive system of humans, has the ability to produce a wide range of antimicrobial compounds, and according to recent studies, its metabolites have a positive role in human digestive system’s performance and can gradually reduce the rate of gastrointestinal related diseases. An important feature which has been studied in this study is the production of the chitinase enzyme that can be used to produce anti-fungus spray (especially against penicillium digitatum ) for fruit storerooms, especially citrus. Materials and Methods: Bacillus subtilis bacterium was cultured in Nutrient Broth medium in order to secrete metabolites of the bacterium that the chitinase enzyme is also contained as one of the metabolites. Then, the isolated metabolites were added at three concentrations of 25, 50, 100 mg/ml to the sabouraud dextrose agar medium, and the fungus was grown on each of the prepared media. A sabouraud dextrose agar plate without the addition of secretory metabolites bacterium which contained penicillium digitatum, was also cultured as a control in incubation at room temperature for one week. Results: As the results indicate, the fungus did not grow in the two cultured plates containing the metabolites including the chitinase enzymes. While it was naturally grown in a plate, cultured free of metabolites. Conclusions: it can be concluded that the secretory chitinase enzyme and some other metabolites of bacillus subtilis bacteria can be replaced with chemical Antifungals which are used in agriculture, therefore, we could have fruits with better qualities and also healthier digestive systems.