Antimicrobial activity of liner lipopeptides produced by Bacillus subtilis HS-A38
海洋枯草芽孢杆菌HS-A38 产直链脂肽活性物质的初步检测

A marine Bacillus subtilis strain HS-A38 was isolated from the sea cucumber intestine. The crude extract of fermentation broth was prepared by methods of hydrochloric acid precipitation and solvent extraction. The extract showed broad-spectrum antimicrobial activity using the paper disc agar diffusion method. Four components, named as compound 1, 2, 3, and 4 were found by the thin layer chromatography and ninhydrin color printing. The compounds with antimicrobial activity were detected and tracked by bioautography of Vibrio parahaemolyticus and triphenyltetrazolium chloride (TTC) coloration on the plate of thin layer chromatography. Two inhibition spots were found, corresponding to compound 1 and 2. The further study showed that the compound 1, 2, and 4 were stable at high temperature. Therefore, it was preliminarily deduced that the four compounds were all straight-chain lipopeptide produced at different phase of fermentation.