贝莱斯芽孢杆菌SX-45提取物对人参根腐病菌抑菌机理研究

Extract of Bacillus velezensis SX-45: The Antifungal Mechanism Against Fusarium oxysporum of Ginseng

人参根腐病是人参生产上的重要病害之一,为了明确贝莱斯芽孢杆菌SX-45提取物对人参根腐病菌的抑菌机理,本研究以贝莱斯芽孢杆菌SX-45和人参根腐病菌为材料,采用硫代巴比妥酸、考马斯亮蓝G-250等方法测定了抑菌机理数据。结果表明,经15μg/mL浓度的贝莱斯芽孢杆菌SX-45提取物处理后,与对照相比,人参根腐病菌菌丝出现畸形、菌丝表面长出突起,菌丝顶端膨大;菌悬液中电导率和菌体丙二醛含量均显著增加,分别是对照组的4.24和42.0倍,且菌悬液的OD_(260)值也从3.48增加到3.83。而随提取物浓度的增加,菌体可溶性蛋白含量、还原性糖含量、NAD-MDH活力和SDH活力与对照相比均呈显著下降趋势,分别下降了97.7%、56.6%、97.5%和48.4%。本研究表明贝莱斯芽孢杆菌SX-45提取物对人参根腐病菌有良好的抑菌作用,为人参病害新型生防菌剂的研发奠定了基础。

Ginseng root rot is one of the serious diseases in the production of ginseng. The objective of this study is to clarify the antifungal mechanism of the extract of Bacillus velezensis SX-45 against Fusarium oxysporum of ginseng. In this study, Bacillus velezensis SX-45 and Fusarium oxysporum of ginseng were used as materials, the antifungal mechanism data were determined by thiobarbituric acid, coomassie bright blue G-250methods etc. The results showed that after being treated with the extract of Bacillus velezensis SX-45 at the concentration of 15 μg/mL, the mycelia of Fusarium oxysporum of ginseng had malformation, the hypha surface protrusion and the hypha tip expansion were observed. The electrical conductivity and malondialdehyde content in the fungal suspension increased significantly, which were respectively 4.24 and 42.0 times those of the control group. The OD_(260)value of the fungal suspension also increased from 3.48 to 3.83. With the increase of extract concentration, the soluble protein content, reducing sugar content, NAD-MDH activity and SDH activity decreased significantly by 97.7%, 56.6%, 97.5% and 48.4%, respectively. This study indicates that the extract of Bacillus velezensis SX-45 has a good inhibition effect on Fusarium oxysporum, and can lay a foundation for the research and development of new biocontrol agent against ginseng diseases.