Study To The Influence Of Immobolization Process On The Trehalose-Synthetase System

This thesis is mainly concerned with the studies on the process of trehalose production from starch by enzymatic method. The cell disruption method was optimized by experiments and the enzyme availability and the trehalose productivity were enhanced by enzyme immobilization.Maltooligosyl trehalose synthase (MTSase) and Maltooligosyl trehalose trehalohydrolase (MTHase) are both intercellular enzyme, therefore, they can just be released by cell disruption. As a result, The toluene disruption was chosen as the best disruption method in lab after comparing all kinds of disruption and the optimum disruption condition was obtained as follows: toluene dosage 5%, treatment time 45min, treatment temperature 30℃.At the same time, we found the enzyme immobilization carrier was able to immoblize selectively maltose synthetase and enhance abnormally the enzyme ability of this dual-enzyme system in residual enzyme liquid. Under the optimum conditions, the mass fraction of trehalose can be got 27.22g/L, its conversion rate of liquefied starch can reach 54% and the reaction time is just 9 hours. Then, it is analyzed primarily that the combined affection of glutaraldehyde and chitosan is critical to this procedure. It is possible that the glutaral pentanedial has the ability to protect the enzyme activity and facility the release of enzyme, and the chitosan is probably able to absorb some kinds of enzyme inhibitor in this dual-enzyme system, which enhances the enzyme ability in end.In addition, the process of enzyme immobilization was investigated on this thesis. By comparing the immobilization effect of several kinds of carriers, 6201 supporter (60~80 item) was chosen as the immobilizing carrier and all relative influencing factors in immobilizing process were optimized. The final result of immobilization enzyme activity is 27.22U/g carrier and the recovery of enzyme activity is 79%. And the enzyme activity in residual liquid is still high, which means the enzyme is still not immobilized uncompletely and this process needs to be optimizated in further.