Location: Crop Bioprotection ResearchTitle: A Brevibacillus fortis isolate produces extracellular antibiotics that inhibit the growth of the onion pathogen Fusarium oxysporum f. sp. cepae and other Fusarium species
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/2019
Publication Date: 7/10/2019
Citation: Johnson, E.T., Bowman, M.J., Dunlap, C.A. 2019. A Brevibacillus fortis isolate produces extracellular antibiotics that inhibit the growth of the onion pathogen Fusarium oxysporum f. sp. cepae and other Fusarium species. Meeting Abstract. [abstract].
Technical Abstract: Onions are susceptible to Fusarium basal rot caused by the soilborne fungus Fusarium oxysporum f. sp. cepae (FOC). Control of this pathogen is difficult with limited genetic resistance in onion. It is therefore worthwhile to identify compounds that inhibit this fungus. We identified a strain of Brevibacillus fortis that secreted antifungal compounds into the growth media. The spent media, diluted 1:1, inhibited growth of FOC conidia after seven hours and killed 90% of conidia after 11 hours. The secreted antifungal compounds retained much of their inhibitory activity after a one hour incubation at 75° C. The spent media also inhibited growth of conidia from F. graminearum, F. proliferatum, F. verticillioides and Galactomyces citri-aurantii. Analysis of the genome sequence indicated a number of antibiotics could be produced by this bacteria isolate. Fractionation of spent media followed by reverse phase LC-MS determined that fractions with antifungal activity contained a mixture of edienes A, B and F and no other known antibiotics. These data indicate that this isolate could be utilized as a biological control organism for onions. Alternatively, development of ediene as a Fusarium control product should be investigated with more experiments.