Research on secondary metabolites from Bacillus amyloliquefaciens strain HN011

Objective To separate and identify secondary metabolites of bio-control bacterium strain HN011 in YPD zymotic fluid.

Method By a small amount of fermentation (1 L), the zymotic fluid was extracted by using liquid-liquid extraction of petroleum ether, chloroform, ethyl acetate and n-butanol. The active portions were determined by Staphylococcus aureus bioassay. The pure compounds were isolated from the active portions by amplifying fermentation. The pure compounds were identified by NMR and mass spectrometry.

Result The bioassay results showed that the activities of different solvent extracts from the zymotic fluid were different. The most obvious activity was ethyl acetate portion, followed by chloroform. The activity of n-butanol portion was weak, and petroleum ether and water portions were not obvious. By amplifying fermentation, fifteen pure compounds were isolated from the bioassay portions, and identified as mainly small molecule cyclic dipeptides based on their structures.

Conclusion The secondary metabolites, which are produced by bio-control bacterium strain HN011 in YPD zymotic fluid, are mainly small molecule cyclic dipeptides.