A novel microorganism designated as Bacillus amyloliquefaciens F5H-5 and a use of a fermented Glycine max (L.) extract prepared by fermenting an aqueous Glycine max (L.) extract with the microorganism in inhibiting 15-lipoxygenase are provided. In particular, the fermented Glycine max (L.) extract can be used in preventing and/or treating a disease in which 15-lipoxygenase inhibition is implicated in a subject, such as cardiovascular diseases.