Abstract:

In order to provide theoretical basis for application of the thermophilic neutral protease, the Folin-phenol method had been used to detect the activity of the protease. The enzyme characteristics and the fermentation conditions were determined by the single factor control experiment. This enzyme's optimal acting temperature and pH value were 75℃ and 7.5 respectively. Cu2+ could activate the enzyme. EDTA has the obvious inhibition on the enzyme, but PMSF had a little inhibition on the enzyme. The protease was postulated to a metal protease. After treating with SDS, the protease of KN1 remained high activity. The KN1 strain's best fermentation conditions were cultured under 37℃ for 4 days, the best carbon resource was the corn-starch and the best nitrogen resource was bean powder. The protease produced by KN1 strain was a kind of thermophilic neutral protease and its optimal temperature was 75℃, and under the proper condition, the activity of the protease could reach as high as 1498.84 U/mL, and the thermophilic neutral protease of KN1will have a good application in the future.