Fusarium Oxysporum Growth Inhibition by a Siderophore-Producing Endophytic Bacterial Strain

In this study, a strain of siderophore-producing endophytic bacterial strain, HS-4, was isolated using improved sugar-aspartic acid (MSA) as a selective medium. The antifungal effect of this bacteria was then assessed against cotton wilt pathogen (Fusarium oxysporum) at varying concentrations of FeCl
₃
. This strain was identified using morphological, biochemical and physiological characteristics, 16S rDNA sequence homology and phylogenetic analysis. Strain HS-4 produced fluorescent siderophores in MSA medium, the relative content of which amounted to 80%. The siderophore produced by strain HS-4 exhibited significant inhibitory activity against F. oxysporum growth under low iron conditions. Strain HS-4 was identified as Bacillus atrophaeus.