Co-production of Multiple Antimicrobial Compounds by Bacillus amyloliquefaciens WY047, a Strain with Broad-Spectrum Activity

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 gyrA sequences.The culture supernatant of WY047 demonstrated inhibition of a wide spectrum of bacteria (Gram positive and Gram negative) and fungi.Nine pairs of primers were designed and six genes (bmyD,fenA,hag,ituA,mrsA,and tasA) of antimicrobial substances were detected by PCR,one of which 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 tasA could not be isolated in this study;however,the broader spectrum suggested huge application prospects.