Antimicrobial activity investigation on Wuyiencin fractions of different polarity.

The aim of this study was to evaluate the antimicrobial activity of Wuyiencin fractions with different polarities against six indicator microorganisms: Rhodotorula rubra, Bacillus subtilis, Bacillus megaterium, Escherichia coli, Cladosporium fulvum and Staphylococcus aureus. The fermentation broth of Wuyiencin was submitted to AB-8 macroporous adsorptive resin and fractionated with solvents of different polarity. The fraction eluted with water had remarkably antimicrobial activity against all the microorganisms investigated except for C. fulvum and S. aureus (MIC <or= 0.0625 mg/mL), probably due to the presence of active components. The fraction eluted with methanol showed potential antimicrobial activity against all the test microorganisms except for R.rubra, with MIC values of 0.5 and 2 mg/mL. In conclusion, fractions eluted with water and methanol, respectively, represent the main active-part of Wuyiencin, and could be emphasized for agricultural applications in the future.