摘要
以里氏木霉(Trichoderma reesei) Rut C-30为产酶菌,研究了碳源、培养温度、初始pH值、碳氮比对木聚糖酶和纤维素酶合成的影响.结果表明,粗木聚糖和亚硫酸盐纸浆混合作为碳源有利于木聚糖酶和纤维素酶的合成;低温有利于木聚糖酶和纤维素酶的合成,但产酶时间较长,高温对木聚糖酶的合成有一定的影响,对纤维素酶的合成能有效地抑制,且产酶时间较短;初始pH值低有利于纤维素酶的合成,初始pH值高则延长了木聚糖酶的合成时间,且强烈抑制纤维素酶的合成;低碳氮比有利于纤维素酶的合成,高碳氮比使得木聚糖酶的合成滞后,能够有效抑制纤维素酶的合成.以粗木聚糖和亚硫酸盐纸浆混合作为碳源,调控培养温度、初始pH值和碳氮比能有效地促进木聚糖酶的合成,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纸浆漂白用木聚糖酶,调控培养方式为:提高碳氮比(7.2)和初始pH值(6.0),在培养初期(1 d)培养温度为35～36 ℃,中后期培养温度25～26 ℃,调控6 d后,木聚糖酶酶活和纤维素酶酶活分别为186.93和0.156 IU/mL,酶活比为1 198.
Effects of carbon resource,culture temperature,initial pH value and carbon-to-nitrogen ratio on xylanase and cellulase synthesis by Trichoderma reesei Rut C-30 have been investigated.The results show that the mixture of corncob xylan and sulfite pulp as carbon resource could stimulate the synthesis of xylanase and cellulase;The culture temperature of 25-26 ℃ could stimulate the synthesis of xylanase and cellulase,the highest xylanases activity((156.53 IU/mL)) and CMCase activity(0.589 IU/mL) could be obtained after 96 h cultivation;When culture temperature was 35-36 ℃,the highest xylanase activity(113.73 IU/mL) and CMCase activity(0.208 IU/mL) could be obtained after 48 h cultivation;Low initial pH value could stimulate the synthesis of cellulase,whereas high initial pH value could prolong culture time of xylanase synthesis and depress the synthesis of cellulase.When the initial pH (values) were 4.0,4.4,4.8,5.4,6.0,the ratios of xylanase to cellulase were 259,327,425,865,1 016,respectively,(after) (72 h) cultivation;Low ratio of carbon to nitrogen could stimulate the synthesis of cellulase,and high ratio of carbon to nitrogen could not only retard the synthesis of xylanase,but also depress the synthesis of cellulase.In the controlled cultivation of T.reesei Rut C-30 with a mixture of 6.5 g/L corncob xylan and 0.5 g/L sulfite pulp as carbon source,high xylanase activity(186.93 IU/mL) and low CMCase activity(0.156 IU/mL) could be obtained after 6 days (cultivation).At the earlier stage,temperature was controlled to 35-36 ℃ with an initial pH value of 6.0 and higher (ratio) of carbon to nitrogen(7.2),while at the later stage temperature was reduced to 25-26 ℃.
出处
《林产化学与工业》
EI
CAS
CSCD
2005年第1期56-60,共5页
Chemistry and Industry of Forest Products
基金
南京林业大学科技创新资助课题(021030285)
