Isolation and screening of indigenous Bacillus speciesfrom the soil of forest parks in Tehran and investigating antifungal activity againstAspergillus tubingensis and Fusarium fujikuroi
Subject Areas : Plant Microbiology
1 - Master of Microbiology ,Department of Microbiology, Faculty of Modern Science and Technology, Department of Medical Sciences, Islamic Azad University, Tehran, Iran
Keywords: Biological Control, Bacillus, Antifungal Metabolites, Gas Chromatography&ndash, Mass Spectometry (GC- MS),
Abstract :
Background & Objectives: Plant diseases caused by pathogenic fungi are problems in the production of agricultural products, which causes decrease of products, appearance of symptoms, and plants death. Useing chemical fungicides have decreased due to high costs, pollution, and resistance.Biological control by Bacillus species is an alternative method. The aim of this research was investigating the antifungal metabolites produced by Bacillus species isolated from the soil of Tehran parks against Aspergillus tubingensis and Fusarium fujikuroi Materials & Methods: To isolate Bacillus species, 5 soils samples were taken. Antifungal activity of the isolated Bacillus species was investigated by welling method. To maximize production of antifungal metabolites, the Nutrient Broth was optimized. The metabolites (Iturin, Fangycin and Surfactin) with the help of methanol solvent were purified. Presence of lipopeptides was confirmed by GC-MS and was identified by Sequencing. Results: 60 species of bacteria were isolated from the soil. 40 species were identified as Bacillus spp. Selected species No. 12 showed the largest diameter of non-growth halo. This species showed the most activity in Nutrient Broth with glucose, yeast extract, pH 7 and temperature of 37 °C after 48 hours. GC-MS confirmed the presence of %68.33 lipopeptides of the Iturin group. sequence matching results showed % 99/80 similarity to the Bacillus toyonensis. conclusion: Isolated Bacillus spp from Tehran soils showed high potential to produce antifungal metabolites that can good substitute for chemical poisons. Thus, antifungal potential’s of isolated indigeniuos bacterial species from our own country can be used for biological control of pests.