SSF For Aminoacylase And Resolution Of DL-Tryptophan

Tryptophan is major used in the field of medicine, such as transfusion of amino acid, the medicine of curing anemia, the adjuvant of histidine. At the same time, tryptophan is the third feed additive in the field of feedingstuff besides methionine and lysine, may be the an up-and-coming talent in the field for its unique action on the growth of animal. at the present time, the overprice (￥600,000/ton) has limited it's application with large scale. If we can cut down the cost, its market demand will increase rapidly. In resent years, it is generally believed that L-tryptophan was prepared through chemical synthesis and enzymatic resolution with low-cost is a hot topic which is widely talked about both at home and abroad.The optimized study that L-tryptophan was prepared through chemical synthesis and enzymatic resolution has been reported. The study mainly included the following contents:Experiment results showed that on (SSF ,solid-state fermentation): the optimism husk/soybean ratio in culture medium is 8:2, the optimism initial water amount on aminoacylase production is 0.7, the most suitable product time of aminoacylase by solid state fermentation is 38-48h and the addition of inducer do anything effect. aminacylase essentially located out of the cell wall. Only adding surfactant or phytic acid could not activate aminoacylase distinctly. The complex promoter including phytic acid and Towen-80 could activate aminoacylase greatly, it could enhance aminoacylase activity to resolve optical N-acyl-DL-tryptophane by 171.94%.As is shown in the experiment: in the process purification of aminoacylase, salt out is 0.4 and 0.6 in Ammonium sulfate Fractionation purify 6 times, Hydrophobic interaction Chromatography on the Aminoacylase experiment show that the purificate multiple could reach 28 times. SDS-PAGE patterns of samples from different step ofpurification show that molecular weight 66,200 Da and 31,000 Da. In the processing of transamination reaction, conditions such as temperature, pH, and metal ions had effects on this reaction, conditions of the reaction were chosen as followed: temperature 55℃, pH7.2, the metal ions such as Co2+ could accelerate the reaction, while Fe2+, AC- and high substrate concentration had some degree of inhibitive effects.The enzyme was immobilized on calcium alginate and the polymer to prepare immobilized enzyme, which was used on the optical resolution of DL-Tryptophan. In order to search better resolution condition, we drew the conclusion as followed: The effect of twice chitin film on Immobilized Enzyme with calcium alginate is transform 20 batchs. The comparison of the different length of link on the immobilization of Aminoacylase could be seen that the longer is better. When dealt with 0.8% glutaraldehyde, the transforming ability was better than usual.