棉花黄萎病原真菌菌体对链霉菌4 种胞外水解酶活性的影响

 以大丽轮枝菌(Verticillium dahliae Kleb. )菌体为唯一碳源,采用液体培养法测定供试病原菌菌体对4 株拮抗链霉菌胞壁水解酶合成的诱导作用;采用平皿气生菌丝水解和显微观察法验证4 株拮抗链霉菌对大丽轮枝菌菌丝的溶解作用。结果表明:①大丽轮枝菌菌体可以诱导供试链霉菌合成几丁质酶、β-1,3-葡聚糖酶、β-葡萄糖苷酶及滤纸纤维素酶;当菌体添加量为10 g·L - 1 ,28℃ 培养7 d 时,上述4 种诱导酶活性可达峰值,其值分别为70. 13 - 129. 05、31. 04 - 37. 34、6. 24 -8． 75 及1. 84 - 3. 35 U。②链霉菌粗酶液对大丽轮枝菌菌丝有溶解作用。③4 株链霉菌菌丝均可缠绕在大丽轮枝菌菌丝上,并在缠绕处使病原菌菌丝溶解。

Influence of Verticillium dahliae mycelium on 4 types of extracellular hydrolases activity of Streptomyces

The inhibitory effect of antagonistic Streptomyces on Verticillium dahliae Kleb.via enzymatic hydrolysis was studied.The pathogen mycelia were used as the sole carbon source,induced effect of V.dahliae on extracellular hydrolases synthesis by 4 tested Streptomyces in liquid cultures was examined;and interaction between Streptomyces and V.dahliae hypha via hydrolysis of aerial mycelium and microscopy were observed.The results showed that synthesis of extracellular chitinase,β-1,3-glucosidase,β-glucosidase and FP cellulase was induced by tested Streptomyces in the presence of V.dahliae.Optimal conditions for extracellular hydrolases fermentation of 4 Streptomyces were related to addition of 10 g·L-1 fungi mycelium at 28℃ for 7 d.The activities of associated extracellular hydrolases were 70.13-129.05,31.04-37.34,6.24-8.75 and 1.84-3.35 U,respectively.Streptomyce crude enzyme solution induced disintegration of V.dahliaemycelia and hypha.All 4 Streptomyces were found capable of twining with V.dahliae hypha,leading to fungal cell wall lysis.