ALG-SiO2杂化凝胶固定化多酶体系催化CO2转化甲醇研究

采用甲酸脱氢酶（FateDH）、甲醛脱氢酶（FaldDH）和醇脱氢酶（ADH） 3种脱氢酶为催化剂，以原型烟酰胺腺嘌呤二核甙酸（NADH）作为电子供体，通过3步连串反应将CO2转化为甲醇。采用正硅酸甲酯原位水解方法将二氧化硅掺杂于海藻酸（ALG）溶胶中,通过双交联制备出新型ALG-SiO2杂化凝胶。与ALG凝胶相比,ALG-SiO2结构更加紧密，酶的泄漏率大大降低,酶活性得以很好保持。将酶包埋于ALG-SiO2后，存放60 d以后或重复使用10次以上，酶活性都能保持80%以上,与之相比，包埋于ALG凝胶中的酶活性几乎完全丧失。

Conversion of CO2 to methanol through multi-enzymes immobilized in ALG-SiO2 composite

Herein,CO_(2) was converted into methanol through three step reduction reactions catalyzed by three different kinds of dehydrogenases,formate dehydrogenase(F_(ate)DH),formaldehyde dehydrogenase(F_(ald)DH) and alcohol dehydrogenase(ADH).Reduced nicotinamide adenine dinucleotide (NADH) was employed as the electron donor.Alginate-silica(ALG-SiO_(2)) hybrid composite bead were prepared for the three dehydrogenases immobilization,through the hydrolysis and condensation of tetramethoxysilane(TMOS) in situ in an alginate solution,followed by Ca~(2 ) crosslinking with blocks of guluronic acid residues.Compared to ALG gel,the ALG-SiO_(2) composite was compact,and feasible for enzyme loading and enzymatic activity retention.After the ALG-SiO_(2)-enzyme biocomposite was stored for more than 60 days,or used for 10 cycles,more than 80% of the relative enzymatic activity could be retained.However,the relative enzymatic activity in the ALG-enzyme biocomposite was decreased almost to zero.