海因酶产生菌的反应条件研究

Study on reaction conditions of Pseudomonas putida producing D-Hydantoinase

利用恶臭假单胞菌(Pseudomonas putida)作为酶源,研究海因酶催化DL-对羟基苯海因合成N-氨基甲酰-D-对羟基苯甘氨酸,以制备D-对羟基苯甘氨酸,并就培养基的优化,反应条件的选择及酶活的影响作了探讨.研究表明,碱性条件下可显著增加酶反应速度,温度对提高海因酶活力有重要影响.培养初始pH值为7.0,温度28℃下培养24 h产海因酶达最高;在最适pH9.0和最适温度55℃下,海因酶活力达到0.7 u/mL,比原基础培养条件下提高3.5倍.

The synthesis of N-carbamoyl-D-p-hydroxyphenylglycine for the preparation of D-p-hydroxyphenylglycine from DL-p-hydroxyphenylhydantoin catalysed by D-hydantoinase from Pseudomonas putida was studied. The optimization of culture medium, the content of the reaction conditions and the effects of enzymatic activity were also explored. The study indicated important impact of alkaline conditions on enzymatic conversion ratio and temperature for increasing enzymatic activity of D-hydantoinase. The production of D-hydantoinase was optimal with an initial pH value of 7.0, the culture temperature of 28 ℃ for 24 h. Under the optimal pH value of 9.0 and temperature 55 ℃, D-hydantoinase activity was 0.7 u/mL, 3.5 folds higher than that under the basic fermentation condition used previously.