Purification and characterization of a novel antifungal protein from Bacillus subtilis strain B29.
An antifungal protein was isolated from a culture of Bacillus subtilis strain B29. The isolation procedure comprised ion exchange chromatography on diethylaminoethyl (DEAE)-52 cellulose and gel filtration chromatography on Bio-Gel P-100. The protein was absorbed on DEAE-cellulose and Bio-Gel P-100. The purified antifungal fraction was designated as B29I, with a molecular mass of 42.3 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), pI value 5.69 by isoelectric focusing (IEF)-PAGE, and 97.81% purity by high performance liquid chromatography (HPLC). B29I exhibited inhibitory activity on mycelial growth in Fusarium oxysporum, Rhizoctonia solani, Fusarium moniliforme, and Sclerotinia sclerotiorum. The 50% inhibitory concentrations (IC(50)) of its antifungal activity toward Fusarium oxysporum and Rhizoctonia solani were 45 and 112 micromol/L, respectively. B29I also demonstrated an inhibitory effect on conidial spore germination of Fusarium oxysporum and suppression of germ-tube elongation, and induced distortion, tumescence, and rupture of a portion of the germinated spores.
Li
Jing
J
Department of Life Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Yang
Qian
Q
Zhao
Li-hua
LH
Zhang
Shu-mei
SM
Wang
Yu-xia
YX
Zhao
Xiao-yu
XY
D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*
D000935:Antifungal Agents; D001426:Bacterial Proteins