Antifungal activity of Bacillus subtilis isolated from soil in Tehran's parks against Fusarium graminearum

Subject Areas : Applied Microbiology

Fatemeh Rafiee ¹ , Mohammad Reza Fazeli ² , Abbas Akhavan sepahi ³ , Zahra Noormohammadi ⁴

1 - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 - of Drug and Food Control, Faculty of Pharmacy and Pharmaceutical Quality Assurance Research Center, Tehran University of Medical Sciences, Tehran, Iran
3 - Department of Microbiology, Faculty of Biological Sciences North Tehran, Islamic Azad University, Tehran, Iran.
4 - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran

Received: 2021-09-30 Accepted : 2022-02-02 Published : 2021-12-22

Keywords: Bacillus subtilis, Fusarium graminearum, antifungal agent, surfactin,

Abstract :

Background & Objectives: Soil microorganisms play an important role in the biological control of pathogenic fungi. The aim of this investigation was to isolate soil-borne Bacillus subtilis with the ability to produce antifngal lipopeptides  that are suitable  for suppressing Fusarium graminearum, which contaminates wheat, corn, potato and a wide range of plants.Materials & Methods: B. subtilis was isolated from the rhizospher of healthy plants of park        slocated in the five areas north, south, east, west and center of Tehran and was identified based on morphological characteristics, biochemical tests and sequencing of 16S rRNA. The antagonistic activity of isolated strains against F. graminearum was investigated by Well method. The strains that inhibited the growth of fungi and showed the greatest inhibition zone, were selected. Surfactin of selected bacteria was purified by methanol method and bacterial metabolites and pure surfactin (Sigma Company) were compared with, high performance liquid chromatography (HPLC).Results: Among 60 isolated strains, 27 strains had antifungal activity. Six strains with the highest fungal inhibition zone (8-16 mm) were selected and their yellow color and transparency was a confirmation to HPLC. Two bacteria with the highest amount of surfactin production by            molecular method showed high similarity with B. subtilis.Conclusion: The results show that Bacillus subtilis isolated from soil are good candidates for    biological control of plant pathogenic fungi and therefore can a suitable alternative to chemical fungicides.