Research About Saccharomyces Cerevisiae Extracellular Activity Of ProteinaseA

In this paper, saccharomyces cerebisiae2144had been chosen for studying onextracellular proteinaseA activity in fermentation broth under different growthconditions.The phenomenon of proteinaseA zymogen early secretion under highconcentration by using YNB culture-medium had been verified.Compared the two differentautoactivated way of proteinaseA.1.The results of the research showed that the activity of proteinaseA was higher in thefermentation conditions of pH5.5,temperature29℃at36~40h under juicegravity of2%~16%.When the concentration got to20%,the high activity appeared16h and thebacterial strain’s logarithmic phase prolonged prominently.And the secondary growth wasappeared in the stationary phase.2.The excreted protein was separated by Sephadex G-25and SephadexG-75,thenanalyzed by SDS-PAGE and specificity fluorescent substrate.Comes to a conclusion onearly secretion of zymogen of proteinaseA at high concentration of glucose by using YNBculture-medium.This is a stress reaction of yeast under high concentration.3.Research the autoactivated ways about proteinaseA via adjusting the fermentationbroth pH and mixing PMSF.Came to a conclusion that both under normal and highconcentration,pH was the main effect factor about proteinaseA activity.The activity washigher when pH5.5under two conditions of culture.