Utilis Yeast Biotransformation To Generate The Cdp-choline

CDP-choline is an important precursor in the biosynthesis of phospholipids and widelyemployed as an effective drug for various kinds of brain injuries.In this paper,TTC andantidione were used in strain screening afrer the candida utilis was treated by UV irradiationand N+ions injection.After the mutation,candida utilis YL-2-24 was obtained.Compared withthe candida utilis YL,the yields of CDP-choline was enhanced 2.01 times.The optimun culture medium ingredients was 4%sucrose, 1.0%peptone, 2.0%NaNO₃,0.5%K₂HPO4,0.5%MgSO₄·7H₂O,0.1%KH₂PO₄.The fermentation process wasoptimied and it was 32℃,starting pH 5.5,rotating speed 230 r/min,incubation for24h,10 % seed culture,250ml flask with 25ml liquid.The transformation ofCDP-choline was 18.90mg/g.When the enzymatic reaction was carried with 10mM CMP,300mM phosphates,50mMcholine phosphate,1000mM Glucose,pH7.4,600mg/ml wet cells,and itwas incubated at34℃for 10h.The transformation of CDP-choline was 18.90mg/g and the rate oftransformation reached 84.4%.