Production of siderophores by the bacterium Kosakonia radicincitans and its application to control of phytopathogenic fungi

The present work aimed to characterize and to improve the production of the siderophore produced by Kosakonia radicincitans and apply it to control of phytopathogenic fungi. The siderophore, characterized by liquid chromatography coupled to tandem mass detection (LC-MS/MS), was identified as enterochelin. The improvement of its production was carried out using different conditions. The higher production of enterochelin (45 mg g−1 dry weight biomass) was reached in a medium with lactose as the carbon source, 0.82 μmol L−1 of iron, at 28 °C and 200 rpm. The siderophore at 60 mg L−1 of concentration inhibited the conidia germination and the mycelial growth of Penicillium expansum, Botrytis cinerea, Rhizopus sp., Alternaria sp. and Cladosporium cladosporioides. Biocontrol of Botrytis cinerea and Penicillium expansum were performed in apple fruit using Kosakonia radicincitans and enterochelin, alone or in a mixture. The mixture was the more effective. In this case, the reduction of decay provoked for B. cinerea reached 52%.