海洋假单胞菌GY-1菌株的抗菌作用及其胞外抗菌蛋白的分离纯化

摘要

In the present study,agar-well diffusion method and Oxford Cup method were used to detect the antimicrobial activities of marine Pseudomonas GY-1 strain.The results showed that GY-1 strain and its fermentation broth had relatively strong inhibition activity against a variety of phytopathogenic fungi,including Bipolaris sorokiniana,Fusarium graminearum,Alternaria solania,Alternaria alternate,Sclerotinia sclerotiorum and Alternaria tenuis Nees.Further study had successfully purified a protein from Pseudomonas GY-1 by ammonium sulfate fractional precipitation,DEAE sepharose fast flow ion exchange chromatography and Sephadex G-75 filtration chromatography.This protein showed obvious inhibition activity against B.sorokiniana.SDS-PAGE analysis revealed that the molecular weight of the protein was about 70.9 kD.%采用对峙培养法和牛津杯法测定海洋假单胞杆菌（Pseudomonas）GY-1菌株和发酵液的抑菌作用。结果表明：GY-1菌株和发酵液对小麦根腐病菌（Bipolaris sorokiniana）、禾谷镰刀病菌（Fusarium graminearum）、菠菜早疫病菌（Alternaria solania）、斑点落叶病菌（Alternaria alternata）、油菜菌核病菌（Sclerotinia sclerotiorum）和小麦叶枯病菌（Alternaria tenuis Nees）等植物病原真菌有较强的抑制作用。发酵液采用硫酸铵分级沉淀、DEAE Sepharose Fast Flow柱层析、Sephadex G-75凝胶层析,以小麦根腐病菌为指示菌进行活性追踪和SDS-PAGE电泳纯度跟踪检测,纯化出一种对小麦根腐病菌具有明显抗菌作用的抗菌蛋白,其分子质量约为70.9kD。