Ensifer adhaerens CAS22-03 fermentation process optimization and enzymatic preparation of D-p-HPG
In order to study the influence factors of the expression activities of D-Hydantoinase(D-Hase)and N-Carbamoyl hydrolase(D-Case)from Ensifer adhaerens CAS22-03,and to improve the catalytic efficiency of the whole-cell catalyzed preparation of D-p-Hydroxyphenylglycine(D-p-HPG)by Ensifer adhaerens CAS22-03,the single factor test and orthogonal test were adopted to optimize the carbon and nitrogen sources,and the fed-batch fermentation process of Ensifer adhaerens CAS22-03 was established.The enzymatic properties of D-Hase and D-Case were analyzed,and the D-p-HPG enzymatic production process based on the whole cell catalysis of Ensifer adhaerens CAS22-03 was developed.The results showed that the optimal carbon and nitrogen sources for Ensifer adhaerens CAS22-03 fermentation were sucrose and yeast extract.In the fed-batch fermentation process,the activities of D-Hase and D-Case were up to 243.6 and 55.8 U/g,which were increased by 56.9%and 46.4%,respectively.The optimal reaction temperature of D-Hase and D-Case is 45 ℃,and the optimal reaction pH is 9 and 8 respectively.In the process of the whole-cell catalytic preparation of D-p-HPG by Ensifer adhaerens CAS22-03,when the substrate concentration was 40 g/L and the enzyme dosage was substrate:bacterium=5:1,the substrate conversion reached more than 95%with the condition of 40℃ and 200 r/min for 10 h,laying the foundation for the industrial enzymatic production of D-p-HPG.
Ensifer adhaerens CAS22-03D-hydantoinaseN-carbamoyl hydrolasefermentation process optimizationwhole-cell catalysis