摘要
超临界二氧化碳流体预处理对纤维素超分子结构及纤维素酶催化反应有重要影响。一定含水量的微晶纤维素用SC CO2 在 1 0MPa,5 0℃处理 30min ,其结构发生了有利于进一步被酶解的变化。上述超临界条件单独作用于纤维素酶时 ,并未造成酶催化活力的降低 ;但与纤维素共同进行SC CO2 处理时 ,纤维素酶则失去催化活性 ,但这种处理却能提高纤维素进一步被酶解的效率。一定范围内处理时的酶用量与酶解效率的增加正相关。纤维素的含水量对SC CO2
The effects of pretreatment of supercritical carbon dioxide (SC CO 2) on the supramolecular structure of cellulose and the cellulase catalyzed reaction were investigated.The cellulase activity was not affected when it was treated with SC CO 2 at 10MPa and at 50℃ for 30 min.But when the cellulase was treated by SC CO 2 in the presence of cellulose,the catalytic activity of the cellulase was lost.The cellulose pretreated with or without cellulase under the same SC CO 2 condition was then hydrolyzed with tresh crude cellulase.The final reducing sugar yield from the hydrolysis of the cellulose pretreated with cellulase was higher than that of the cellulose pretreated without cellulase.It was also found that the improvement of the enzymolysis had a direct relevance with the amount of cellulase used during the SC CO 2 pretreatment.The moisture content of cellulose before SC CO 2 pretreatment had an obvious influence on the subsequent enzymolysis.When the moisture content of cellulose was 60 %( W/W ),the reducing sugar yield was higher than when the moisture content was over 100%( W/W ). The FT IR spectra showed that the structure of the cellulose pretreated with cellulase under the SC CO 2 condition was diffe rent from that of the cellulose pretreated without cellulase. In the presence of the enzyme,the strength of the hydrogen bonds and the I β phase at 710cm -1 in the crystalline cellulose was weakened.These results suggest that the change in the cellulose structure induced by the SC-CO 2 treatment favous the subsequent enzymolysis.
出处
《生物工程学报》
CAS
CSCD
北大核心
2004年第5期770-773,共4页
Chinese Journal of Biotechnology
基金
科技部重点基础研究发展规划项目 ("973")资助 (No .2 0 0 3CB7160 0 6)~~
