小麦赤霉病拮抗菌P72抗菌物质的分离纯化和性质研究

目的]研究小麦赤霉病拮抗菌P72的抑菌活性及稳定性。方法]将Bacillus subtilisP72接种于发酵培养液中,接种量5%,28℃摇床培养48 h后,8 000 r/min,离心10 min取菌株发酵离心所得上清液进行分离纯化、遗传稳定性、热稳定性及酸碱稳定性测定。结果]P72菌株发酵上清液经过盐析、透析后进行DEAE-52离子交换层析,用0.5 mol/LNaCl溶液洗脱的蛋白对小麦赤霉病菌的拮抗能力最强。SDS-PAGE电泳显示具有抗菌作用的蛋白分子量约为40 kD。经过稳定性的试验测定,该抗菌物质的拮抗活性具有遗传稳定性,在60℃有较高的稳定性,无菌液对酸具有稳定性,在碱性溶液中不具有稳定性。结论]小麦赤霉病拮抗菌P72对小麦赤霉病菌的拮抗能力较强,抗菌活性较稳定,且热稳定性较好,有广阔的开发前景。

Study on Property and Purification of Antagonistic Bacteria P72 against Wheat Scab

Objective] The antibacterial activity and stability of antagonistic bacteria P72 against wheat scab were studied in the experiment.Method] The Bacillus subtilis P72 was inoculated in fermentation culture and the inoculation amount was 5%.The Bacillus subtilis P72 was cultured on shaking table at 28 ℃ for 48 h and centrifuged at 8 000 r/min for 10 min.The supernatant of fermentation broth was purified then it was detected genetic stability,thermal stability and pH stability.Result]The supernatant of fermentation broth of P72 strain was conducted DEAE-52 ion exchange chromatography after salting-out and dialysis and the protein which was eluted by 0.5 mol/L NaCl solution possessed the strongest antagonistic ability against wheat scab pathogen.The SDS-PAGE electrophoresis showed that molecular weight of protein with antibacterial effect was 40 kD.Through the stability test,the antagonistic activity of this antimicrobial substance was heritable.At 60 ℃,the sterile liquid was stable in acidic solutionand unstable in alkaline solution.Conclusion] The antagonistic bacteria P72 had strong antagonistic ability to wheat scab pathogen and stable antibacterial activity as well as thermal stability,so it would possess a wide development prospect.