Sequential co-immobilization of β-glucosidase and yeast cells on single polymer support for bioethanol production  

作　　者：Bin He Xing Zhu Changwen Zhao Yuhong Ma Wantai Yang 

机构地区：[1]State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology [2]Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology [3]Department of Mechanical Engineering, The University of British Columbia [4]Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology [5]Beijing Advanced Innovation Centre for Soft Matter Science and Engineering, Beijing University of Chemical Technology

出　　处：《Science China Chemistry》2018年第12期1600-1608,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (51521062, 51103009, 51473015);the Innovation and Promotion Project of Beijing University of Chemical Technology and the Beijing Natural Science Foundation (2162035)

摘　　要：Co-immobilization of enzymes and microorganism is an effective way to enable cells to use nonmetabolizable substrates and accelerate reaction rate of overall process. Herein, a facile strategy to separately co-immobilize β-glucosidase(BG) and yeast cells on non-woven fabrics was developed. The BG was firstly in situ entrapped into poly(ethylene glycol)(PEG) network grafted on non-woven fabrics by visible light induced living/controlled graft polymerization. Then re-graft polymerization was performed on the as-formed BG loaded layer by taking advantage of living-grafting polymerization on its surface to in situ encapsulate yeast cells into the second PEG network layer. This layered structure of co-immobilization avoided possible interference between enzyme and cells. Viability assay of yeast cells demonstrated that most of cells were viable after immobilization. While immobilized BG showed decreased V_(max) compared to free BG, indicating that entrapping BG into inner PEG network layer restricted its accessibility with substrates. This co-immobilization sheet could successfully convert cellobiose to ethanol and a maximum of 98.6% bioethanol yield can be obtained after 48 h of simultaneous saccharification and fermentation(SSF). The co-immobilization sheet showed excellent reusability and could still reach more than 60% of original ethanol yield after reusing for 7 batches. Compared with the mixed co-immobilization, the sequential layered immobilization in this system showed better stability and higher ethanol yield.Co-immobilization of enzymes and microorganism is an effective way to enable cells to use nonmetabolizable substrates and accelerate reaction rate of overall process. Herein, a facile strategy to separately co-immobilize β-glucosidase(BG) and yeast cells on non-woven fabrics was developed. The BG was firstly in situ entrapped into poly(ethylene glycol)(PEG) network grafted on non-woven fabrics by visible light induced living/controlled graft polymerization. Then re-graft polymerization was performed on the as-formed BG loaded layer by taking advantage of living-grafting polymerization on its surface to in situ encapsulate yeast cells into the second PEG network layer. This layered structure of co-immobilization avoided possible interference between enzyme and cells. Viability assay of yeast cells demonstrated that most of cells were viable after immobilization. While immobilized BG showed decreased V_(max) compared to free BG, indicating that entrapping BG into inner PEG network layer restricted its accessibility with substrates. This co-immobilization sheet could successfully convert cellobiose to ethanol and a maximum of 98.6% bioethanol yield can be obtained after 48 h of simultaneous saccharification and fermentation(SSF). The co-immobilization sheet showed excellent reusability and could still reach more than 60% of original ethanol yield after reusing for 7 batches. Compared with the mixed co-immobilization, the sequential layered immobilization in this system showed better stability and higher ethanol yield.

关 键 词：IMMOBILIZATION GRAFT polymerization BIOETHANOL enzyme YEAST cells 

分 类 号：TQ223.122[化学工程—有机化工]