Beauvericin from the endophytic fungus, Fusarium redolens, isolated from Dioscorea zingiberensis and its antibacterial activity.

From the fungal endophyte, Fusarium redolens Dzf2, isolated from rhizomes of the Chinese medicinal plant Dioscorea zingiberensis, beauvericin was obtained by TLC in combination with bioautographic antibacterial assay. The compound was identified by spectroscopic and physicochemical means. The median effective inhibitory concentration (IC50) values of beauvericin against six test bacteria (Bacillus subtilis, Staphylococcus haemolyticus, Pseudomonas lachrymans, Agrobacterium tumefaciens, Escherichia coli and Xanthomonas vesicatoria) were between 18.4 and 70.7 microg/mL. The beauvericin content of F. redolens Dzf2 mycelia was 9.60 mg/g dw, and beauvericin yield 62.4 mg/L. The obtained results show the potential use of the endophytic fungus for its biological role in providing its host plant with protection, as well as the possible development of beauvericin as an antibacterial.