摘要
以匍枝根霉TP-02(Rhizopus stolonifer TP-02)为出发菌株,首次利用淀粉水解液为主要碳源,快速合成纤维素酶。从碳源、氮源、培养温度、初始p H、装液量和接种量等方面研究该菌株的产酶条件。获得最佳培养基和培养条件为:10%淀粉水解液,麸皮浸出汁5%,NH_4Cl 0.5%,KH_2PO_40.5%,MgSO_4·7H_2O 0.4%,CaCl_20.4%,酵母粉0.6%;发酵温度30℃,装液量80 m L/(250 m L),初始p H 5.0,接种量8%。通过摇瓶实验优化培养基和培养条件后,获得滤纸酶活为9.66 IU/m L。研究中进一步利用该培养基在5 L发酵罐中发酵至60 h时酶活达到最大值,其中滤纸酶活、外切酶活、内切酶活和β-葡萄糖苷酶分别为16.51、15.39、11.48和6.17 IU/m L。与以往纤维素类物质为碳源发酵产纤维素酶相比,淀粉水解液发酵获得的纤维素酶酶系组成有了较大的变化,特别是关键的外切酶活有了大幅度提高,而发酵时间缩短了将近1倍。
Starch hydrolyzate was first utilized as the main carbon for Rhizopus stolonifer TP-02 to achieve a highly efficient production of cellulase. The fermentation conditions including carbon source,nitrogen source,temperature,initial p H,medium volume,and concentration of inoculum were optimized. The optimal medium and culture conditions were confirmed as follows: starch hydrolyzate of 10%,wheat bran extract of 5%,NH_4Cl of 0. 5%,KH_2PO_4 of 0. 5%,MgSO_4·7H_2O of 0. 4%,CaCl_2 of 0. 4%,yeast extract of 0. 6%,fermentation temperature of 30℃,medium volume of 80 m L /( 250 m L),initial p H 5. 0 and inoculation concentration of 10%. In the condition mentioned above,the filter paper activity could peak at 9. 66 IU / m L. Enlarging the fermentation in a 5 L fermenter,the activity of cellulase reached the maximum value after 60 h. The activity of filter paper,exoglucanase,endoglucanase and β- glucosidase was 16. 51 IU / m L,15. 39 IU / m L,11. 48 IU / m L and 6. 17 IU / m L,respectively. Compared with conventional cellulose-based material as a carbon source for fermentation of cellulose enzyme,the composition of cellulase obtaining from fermentation of starch hydrolyzate had significant changes. Especially the critical exonuclease activity had greatly improved. The fermentation time had been nearly doubled shortened.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2016年第6期93-97,共5页
Food and Fermentation Industries
基金
国家自然科学基金项目(31270135)
关键词
匍枝根霉
淀粉水解液
发酵
纤维素酶
Rhizopus stolonifera
starch hydrolysate
fermentation
cellulose