The Anti-TMV Activities and Properties of Alkaline Protease from Bacillus subtilis W-QX-1

In order to find a new plant virus inhibitor from native source,the study purified an alkaline protease from the culture of Bacillus subtilis W-QX-1,and primary determined its anti-TMV activity and its properties.The test result indicate: The optimum temperature for hydrolysis of casein were 50℃;The optimum pH were 7.8 in borate buffer and 8.0 in Tris buffer, respectively;The enzyme was stable up to 45℃,within the pH range of 6~10;The alkaline protease could hydrolyze some natural protease like casein、 soluble silk fibroin、 pure fibroin、 bovine serum albumin and gelatin.By half leaf method on Nicotiana glutinosa,the inhibition rate against TMV was 53.40% when the concentration of the alkaline protease was 50 mg/L,and the efficiency of inhibiting infectivity of TMV of 48 h applied before inoculation was 50.35% when concentration of the alkaline protease was 200 mg/L.Therefore,the alkaline protease which had a stable character and a broad action spectrum could inactivated TMV effectively.