Activity Changes Of Several Extracellular Enzymes In Different Growth Periods Of Pleurotus Citrinopileatus

The saprophytic edible fungus does not contain the chloroplast, is the heterotrophic organism, can secrete many kinds of lyoenzymes, which hydrolyze cellulose, hemicellulose, lignin, pectin, protein in environment into small molecular material, for hypha cell use. The activity change of lyoenzyme is related with the type of edible fungus, the different physiological development period and the culture medium composition and so on.This research sampled plants of pleurotus citrinopileatus cultivated with fermented cotton seed shell in flowerpot in different periods, then determined activities changes of nine kind of lyoenzymes. The results are as followings:1. During entire vegetal period of Pleurotus citrinopileatus, The activities of extracellular CMCase (carboxymenthel cellulase), Fpase (fliter paper cellulase),β-glucosidase, Hcase (hemicellulase), amylase, pectase, laccase, peroxidase and protease all can be tested.2. The activity change of CMCase is low in the hypha growth stage(5.2U), but increases steeply after formation of culture medium, then reaches its peak in button period(25U), and retains comparatively high till the maturity of fruit-body(25U), afterwards it decreases quickly to 9.4U. After formation of culture medium for the second generation, the activity of lyoenzymes again increases, and reaches highest level at primodial stage(20U), and decreases gradually afterwards to 12U.3. The activity of FPlase is also low at hypha growth period(4.9U), and then after the formation of culture medium it increases steeply to 7.4U. After primodial period of fungus when the activity of Fplase reaches to 16U, it begins to decrease to 9.8U until the formation of culture medium for the second flush. Between primodial formation and fruit-body maturity period, the activity retains high up to 13U and then decreases to 4.4U.4. The activity ofβ-glucosidase remains low(3.3U), and increases to 8.6U at the formation of culture medium. But there is no obvious activity change and apparent activity peak between two generations of fungus.5. Though low at phypha growth period(7.7U), the activity of HCase increases high up to16U after formation of culture medium, and reaches its peak 48.9U at primary stage. However, it decreases quickly to 26.4U with the maturity of body-fruit till the formation of culture medium for the second generation fungus. Another peak (36.7U) comes at the primary stage of second generation, and again gradually decreases afterwards to 14.5U .6. Phypha of priamry stage is of low amylase activity (16.5U). Ten days later the activity begins to increase and remains comparatively high (34.5U) till the fruit-body maturity, and then decreases gradually to 6.4U.7. The activity of Pectase remains low (18.5U and 9.1U) between the primary stage of Phypha and formation of anlage for the first generation fungus. The increase comes after the formation of anlage until the end of the second generation cultivation, but the range remains between 30.3U and 6.4U.8. Though the activity of laccase and peroxidase goes up and down during cultivation, on the whole, its inclination is decreasion.9. At pypha stage, the activity of proteas is comparatively low (182U), then increases steeply to 312U after formation of anlage, reaching to its peak at 617U at primary stage of fungus, and this lasts until the end of the second generation cultivation.The above results show that pleurotus citrinopileatus has a complete set of extracellular cellulase as the sustance foundation for cellulase decompostion. At boby-fruit growth period of pleurotus citrinopileatus, the continuous activity increase of CMCase, FPase, Hcase, protease and pectase accelerates the degradation of substance with large molecule, such as cellulose, hemicellulose, protein and pectin, and thus provides carbon and nitrogen for body-fruit growth.