Screening of actinomycetes from marine environments and the inhibitory activity against pathogen Staphylococcus aureus

摘要

Forty-one actinomycetes isolated from sea sand of beach in Weihai were tested using the agar diffusion method, and Staphylococcus aureus was selected as the tested bacteria. Strains with significant inhibitory activity were chosen to ferment in the GS medium, then the supernatant was extracted using ethyl acetate, and the vitro assay of crude extracts was performed. Results indicate: there are eight strains having significant activity, accounting for 31.7% of the total. The suppression of MA27 and MA41 are much significant than the other six strains, and their inhibitory diameter is 15.00±1.14 mm and 14.00±2.83 mm, respectively. Six extracts of antibacterial metabolites with ethyl acetate were assayed. Three strains (MA27, MA36, SHXF02) have antibacterial activity under the concentration of 2 mg/disc, their inhibitory diameter is 29.00±2.64 mm, 18.67±2.31 mm and 14.33±0.58 mm, respectively.