初始pH对合成木聚糖酶和纤维素酶的影响

Effects of the Initial pH on Xylanase and Cellulase Synthesis by Trichoderma reesei Rut C-30

以里氏木霉 (Trichodermareesei)RutC 3 0为产酶菌 ,研究了不同初始 pH值对木聚糖酶和纤维素酶合成的影响。结果表明 ,初始 pH较低有利于纤维素酶的合成 ,初始 pH值高则延长了产木聚糖酶的时间 ,且强烈抑制纤维素酶的合成 ,致使木聚糖酶活与纤维素酶活的比值提高 ,从而有利于选择性合成木聚糖酶。初始 pH值分别为 4 .0、4 .4、4 .8、5.4、6.0时 ,培养72h ,木聚糖酶活与纤维素酶活的比值分别为 2 59、3 2 7、4 2 5、865、1 0 1 6。随着初始 pH值的增加 ,里氏木霉对培养液中还原糖的消耗能力在降低 ,初始 pH值在 4 .0～ 4 .8范围内 ,培养 4 8h时还原糖浓度达到最低 ,并且维持在低浓度的水平上。当初始 pH值在 5.4～ 6.5范围内 ,培养 72h时还原糖浓度才达到最低 ,并且培养液中还原糖浓度较高 ,初始 pH值提高到 6.5时 ,培养液中还原糖浓度维持在较高水平上 。

The effects of the initial pH value on xylanase and cellulase synthesis by Trichoderma reesei Rut C 30 have been investigated.The results show that low initial pH value could stimulate the synthesis of cellulase,whereas the high initial pH value could prolong culture time of xylanase synthesis and depress the synthesis of cellulase,therefore the high initial pH value could favourate the synthesis of cellulase poor xylanase.When the initial pH values were 4.0,4.4,4.8,5.4,6.0,the ratio of xylanase to cellulase was 259,327,425,865,1 016,respectively,after 72 h cultivation.The ability of consumption of reduce sugar in the culture filtrate decreased by Trichoderma reesei with increasing of the initial pH value,When the initial pH value was 4.0～4.8,the concentration of reduce sugar in the culture filtrate maintained a low level,and reached the lowest concentration in 48 h;When the initial pH value was 5.4～6.0,the concentration of reduce sugar in the culture filtrate was high,and reached the lowest concentration in 72 h;When the initial pH value was 6.5,the concentration of reduce sugar in the culture filtrate was higher,and the synthesis of xylanase and cellulase was depressed.