乙醇添加条件下纤维素分解菌对棉秆的降解研究

Degradation of cotton stalks by cellulolytic strains with ethanol addition

检测了3株纤维素分解菌Q59、J71和J74降解棉秆的发酵周期,在此基础上,通过完全随机区组试验研究了3株菌在乙醇添加不同浓度(6%、4%、2%)和不同时间(1d、1/2周期、全周期)降解棉秆的酶活和糖化率。结果表明,3株纤维素分解菌发酵周期分别为9d、6d和6d;3株菌均能在添加一定乙醇条件下生长并获得较高的酶活和糖化率,乙醇浓度和添加时间对纤维素分解菌降解棉秆酶活和糖化率均有显著影响,添加乙醇浓度为2%、于全周期添加时3株菌均能获得最高的CMC酶活、FPA酶活和糖化率,说明,乙醇浓度越低、添加时间越晚,越有利于菌株获得高的酶活和糖化率。实际生产中,可考虑调控乙醇的浓度和出现的时间,从而获得较高的酶活和糖化率。

Fermentation periods of degrading cotton stalks by three cellulolytic strains were detected at first. Then a random block design was applied to study the cellulase activity and glycosylated ratio of the three strains in the course of degrading cotton stalks under different ethanol adding concentration （6%, 4% and 2% ） and adding time （ 1d, 1/2 period and full period）. The results showed that the fermentation periods of three cellulolytic strains were 9d, 6d and 6d; all the strains could grow and reach high cellulase activity and glycosylated ratio when adding appropriate etha- nol; the concentration and adding time affected cellulase activity and glycosylated ratio significantly, when the ethanol concentration was 2% and adding time was full period, the three strains could gain the highest CMCase, FPase and glycosylated ratio, which revealed that lowered the ethanol concentration and delayed the adding time, the strains could achieve higher cellulase activity and glycosylated ratio. In production, considering ethanol concentration and adding time as key factors could get higher cellulase activity and glycosylated ratio.