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Purification and identification of a novel antifungal protein from Bacillus subtilis XB-1

Ren, Jianjun, He, Wenhao, Li, Chunyu, He, Song, Niu, Dongze
World journal of microbiology & biotechnology 2019 v.35 no.10 pp. 150
Bacillus subtilis, Monilinia fructicola, ammonium sulfate, antifungal properties, bacteria, biological control, chitosanase, electrospray ionization mass spectrometry, ion exchange chromatography, molecular weight, pathogens, polyacrylamide gel electrophoresis, proteins, sodium dodecyl sulfate, tandem mass spectrometry
This study aimed to characterize a powerful antifungal component from bacteria. Bacillus subtilis strain XB-1, which showed maximal inhibition of Monilinia fructicola, was isolated and identified, and an antifungal protein was obtained from it. Ammonium sulfate precipitation, ion exchange chromatography, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were used to purify and identify the proteins secreted by B. subtilis XB-1. Analyses revealed that purified fraction V had the strongest antifungal effect, with the largest pathogen inhibition zone diameter of 4.15 cm after 4 days (P < 0.05). This fraction showed a single band with a molecular weight of approximately 43 kDa in SDS-PAGE. Results from SDS-PAGE and liquid chromatography electrospray ionization tandem mass spectrometry analyses demonstrated that fraction V was likely a member of the chitosanase family. These results suggest that B. subtilis XB-1 and its antifungal protein may be useful in potential biocontrol applications.