Investigation of biocontrol properties of some siderophore producing soil bacteria

Siderophores are extracellular metabolites containing various chemicals with iron binding properties in organisms. These compounds are mainly produced by microorganisms. In this study, 72 bacterial isolates were isolated from the rhizosphere of different plants and their ability to produce siderophores was determined using CAS Agar medium. It was determined that 18 bacterial isolates produced siderophores and siderophore production indices ranged between 1.2-4.3. Biocontrol activities of all bacterial isolates isolated from rhizosphere soil against Fusarium oxysporum and Alternaria alternata, which are plant pathogens isolated from soil, were determined in vitro. Among the bacterial isolates, 8 isolates suppressed F.oxysporum mycelial growth between 54.54-72.72 % compared to the control and 5 of these isolates were found to have the potential to produce siderophores. In the biocontrol evaluation against Alternaria alternata, 38 of 72 isolates showed biocontrol feature by inhibiting mycelial growth at rates ranging from 42.5-80% compared to the control. Among these isolates, 16 isolates out of 18 isolates which were found to produce siderophores showed biocontrol properties against A. alternata. Isolates showing both siderophore and biocontrol properties against both pathogenic fungi species were identified as Bacillus amyloliquefaciens ssp. plantarum, Bacillus subtilis, Enterobacter bugandensis, Acinetobacter calcoaceticus, Pseudomonas putida, Bacillus mojavensis using MALDI TOF MS identification method. This study is important in terms of being a source for other studies on siderophore. These data on siderophore can be used in plant protection and agricultural applications of bacteria.