摘要
A bacterial strain WY047 was isolated from fermented grains and the bacterium was identified as Bacillus amyloliquefaciens, based on morphological, biochemical, and physiological tests, and analysis of 16S rRNA and gyr A sequences. The culture supernatant of WY047 demonstrated inhibition ofa wide spectrum ofbacteria(Gram positive and Gram negative) and fungi. Nine pairs ofprimers were designed and six genes( bmyD, fenA, hag, ituA, mrsA, and tasA) ofantimicrobial substances were detected by PCR, one ofwhich was isolated by 80% ammonium sulfate precipitation, D201 resin anion-exchange chromatography, and Sephadex G-75 filtration column. The purified peptide was estimated to be 35,207 Da and identified as flagellin by MALDI-TOF mass spectrometry. Another four antimicrobial substances were extracted with methanol and identified as iturin A, fengycin, bacillomycin D, and mersacidin through the liquid chromatography–mass spectrometry(LC–MS) method. The sixth possible peptide encoded by tas A could not be isolated in this study; however, the broader spectrum suggested huge application prospects.
A bacterial strain WY047 was isolated from fermented grains and the bacterium was identified as Bacillus amyloliquefaciens, based on morphological, biochemical, and physiological tests, and analysis of 16S rRNA and gyr A sequences. The culture supernatant of WY047 demonstrated inhibition ofa wide spectrum ofbacteria(Gram positive and Gram negative) and fungi. Nine pairs ofprimers were designed and six genes( bmyD, fenA, hag, ituA, mrsA, and tasA) ofantimicrobial substances were detected by PCR, one ofwhich was isolated by 80% ammonium sulfate precipitation, D201 resin anion-exchange chromatography, and Sephadex G-75 filtration column. The purified peptide was estimated to be 35,207 Da and identified as flagellin by MALDI-TOF mass spectrometry. Another four antimicrobial substances were extracted with methanol and identified as iturin A, fengycin, bacillomycin D, and mersacidin through the liquid chromatography–mass spectrometry(LC–MS) method. The sixth possible peptide encoded by tas A could not be isolated in this study; however, the broader spectrum suggested huge application prospects.
