棘托竹荪深层发酵胞外酶活性的研究

Study on Extracellular Enzyme Activity from Dictyophora echino-volvata Zane during Submerged Fermentation

以棘托竹荪菌株为试材,采用液体培养的方法研究棘托竹荪深层发酵过程中6种胞外酶的酶活性变化,并对菌丝生物量进行了测定。结果表明:酶活性与菌丝生物量增长有密切关系。菌丝生物量增加呈'S'曲线,第4~6天增长最快。棘托竹荪菌丝生物量达到最大值之前,羧甲基纤维素酶和淀粉酶活性出现峰值。过氧化物酶、漆酶、多酚氧化酶和蛋白酶的活性与菌丝生物量同步增加。说明发酵过程中棘托竹荪菌丝首先分解利用淀粉和纤维素,然后利用木质素和蛋白质作为碳源和氮源。要提高棘托竹荪深层发酵效率,缩短培养周期,就必须在其菌丝达到最大生物量之前保证碳源和氮源的均衡供给。可根据不同酶的分泌高峰期,确定菌丝的营养利用情况和发酵周期,以收获最大菌丝生物量。

Bacterial strain of Dictyophora echino-volvata Zane was used as test material,the activity variation of six extracellular enzymes from Dictyophora echino-volvata Zane during submerged fermentation was studied,by the methods of liquid culture,and the biomass of mycelium were determined.The results showed that the enzyme activity was closely related with the mycelium biomass.Increase in mycelum biomass was of 'S' curve,and the fastest growth of the mycelium occurred at earlier developmental stage,especially the first 4～6 days.The biomass of mycelium reaches its maximum after the enzyme activity peak of carboxymethyl cellulose enzyme and amylase,whereas the activity of other four enzymes increased simultaneously with that of the mycelial biomass of D.echino-volvata.Zana These findings demonstrated that the mycelium deomposed starch and cellulose first during fermentation,then lignin and protein were used as their C and N sources.To promote the fermentation efficiency and the reduction of culture period,sufficient C and N sources will be provided before the maximum biomass of mycelium came out.To achieve the maximum mycelium biomass,nutrition allocation and fermentation cycle of the mycelium should be considered based on the activity peak time of different enzymes.