| Celite is one of inorganic carrier with large specific area,cheap,Chemical stability and widespread on earth.It was used in many kinds of the chemicals and foods.In this work,Candida sp.99-125 lipase was immobilized by physical adsorption onto celite,and it will be a new large-scale immobilized enzyme-producing process coupled with drying and immobilization.In this work,the producing process of lipase immobilized celite was explored,and the reaction effects of different inorganic carriers were compared.The immobilization of celite as carrier and the average conversion of immobilized enzyme than other inorganic carriers were investigated.The rate of lipase immobilized celite conversion is 40%to others,and it is 7 times to enzyme powder.For the synthesis of tetradecanoic acid ester and vitamin A palmitate synthesis system,the optimum type of celite was researched.Finally the pH 7.0 of Jilin celite is chosen.Then,the additives for the large-scale preparation process were selected.The results showed that the efficiency of the immobilized enzyme was 1.5 times higher than that of the immobilized enzyme without additive.In addition,after the selection of several kinds of hydrophobic agents and addition methods,it was found that the hydrophobes added with APTES aqueous phase were 5%higher in conversion rate and 2 times in repeat used than other hydrophobes.APTES was added in an amount of 2%(w/w)of enzyme.Because of hot air is introduced in the spray granulation,the TG is added in order to increase the thermal stability of lipase.Through the experimental data can be seen.Lipase is cross-linked by TG,at 60?,the stability greatly increased.Compared with no cross-linked lipase s,the enzyme activity in 70 min of is same to activity.In the process of large-scale preparation,the mixing method is optimized,and the stiirring method of the homogenizer is adopted,and the efficiency is improved by 30%compared with the stirring tank.In the process of scale preparation of lipase immobilized celite by enzyme powder,the optimal operating parameters were selected at 80 ?.and 15 mL/min,and the ratio of enzyme and celite(w/w)was 1:17,1:14,1:8,1:4,the hydrolysis enzyme activity of the lipase immobilized celite was improved by 30%compared with the lipase immobilized celite in small-scale producing.And the esterilication activity of the lipase immobilized celite was improved by 5%compared with the lipase immobilized celite in small-scale producing.At 4?,when the water activity was maintained at 0.376,the esterilication activity of the lipase immobilized celite has been maintained in 6 months.In addition,the technology of preparation of lipase immobilized celite after centrifugation of the fermentation broth was developed,and the immobilized enzyme preparation was prepared directly from the supernatant.The ratio of enzyme to celite(w/w)was 0.75:1,1:4,1:14 lipase immobilized celite preparation is producted.The hydrolysis enzyme activity of the lipase immobilized celite was same to the process of scale preparation of lipase immobilized celite by enzyme powder.but the esterification activity is low.it may be improved for the addition water drying process.Finally,it is applicated on enzymatic synthetic ester,a lipase immobilized celite of high proportion of celite was used in the reaction of 30 L reactor for bio-enzymatic synthesis of bio-based plasticizer.It was used for 6 batches,the average conversion rate of 85%.A lipase immobilized celite of medium proportion of celite can be used in 5L reactor for biological enzymatic synthesis of VA ester system,it can be used for 8 batches continuously,the conversion rate of 85%.In addition,the synthesis process of VA medium chain fatty acid ester was developed,and the reaction time was greatly reduced,and the reaction time was reduced to 80%.For A lipase immobilized celite of low proportion of celite used in 30 L reactor for enzymatic synthesis of sterol ester successfully,it can be uesd for 7 batches continuously,the conversion rate of 90%. |
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