Abstract:

Helicoverpa armigera chitinase was used as the target to screen strains able to inhibit chitinase by transparent ring plate screening method and DNS colorimetric screening method. A total of 29 strains including strain A0901# were selected out of 500 ones. For separation and purification, the fermentation products of strain A0901# were subjected to alcohol precipitation, protein removal by Sevag s method and gel filtration chromatographic fractionation, and a pure bioactive material was obtained. This bioactive material exhibited a single HPLC peak with a retention time of 15 min. Its inhibition rate on chitinase was evaluated by DNS colorimetric method to be 54.2%. Moreover, its formula was C9H18O10 according to the IR and mass and element analyses, and its nature also proved a multiple hydroxyl compound.

Key words: chitinase, inhibitor, screening, isolation