Preparation Of Hydroxycobalamin By Photolysis

Cobalamin,also called vitamin B₁₂,is widely used as a therapeutic and nutritional supplement in the fields of clinical medicine,feed and food.The traditional production method of hydroxylcobalamin was to produce cyanocobalamin and then to synthesize hydroxycobalamin by chemical method.Hydroxycobalamin belongs to the VB₁₂ family?cobalamin?and is an updated alternative to cyanocobalamin.In this study,Propionibacterium freudenreichii,which is preserved and bred in the laboratory,was used as the original strain.High yield strain WY-380 was obtained by propionic acid pressure screening,which improved the yield of vitamin B₁₂2 and propionic acid.The process of synthesis of hydroxycobalamin by dynamic continuous photolysis of deoxyadenosine cobalamin and the adsorption and extraction process of hydroxycobalamin by macroporous resin were studied.Thus the production process of hydroxycobalamin directly from photolysis of fermentation product adenosine cobalamin was established.This process replaced the traditional production method.Therefore,it reduced the complexity of the process,increased the economy of production,and avoided the use of cyanide in the production process.The main research contents and results of this study are as follows:1?Screening of propionic acid resistantstrains of Propionibacterium freudenreichiiWith the original strain of the selected strain preserved in the laboratory,a 30g/L propionic acid resistant strain WY-380 was obtained by propionic acid pressure screening method.Optimized by the fermentation process of acid-resistant strains,When the 2L shake flask was fermented to 84h,Add DMB conversion 48h,fermentation was finished,The results showed that the contents of vitamin B₁₂ and propionic acid were 23.2 mg/L and 38.3g/L respectively,which were 81.25%and 5%higher than the original strain in the fermentation experiment.2?Study on the preparation of hydroxycobalamin by photolysis of deoxyadenosylcobalaminThe photolysis process of deoxyadenosine cobalamin under different conditions was studied,and the preparation process of hydroxycobalamin was established.Static experimental results showed that when the ultraviolet light intensity is 13000Lux,the complete photolysis conversion time of 22mg/L deoxyadenosine cobalamin was 15min.Dynamic photolysis experiments were carried out in a continuous ultraviolet reactor,and the results showed that when the flow rate was 40ml/min,deoxyadenosine cobalamin with a concentration of 74.2 mg/L or less could be completely photolyzed.3?Extraction of hydroxycobalamin by macroporous resinThe extraction process of hydroxcobalamin obtained by photolysis was carried out using macroporous resins.The static adsorption and desorption processes of D-85,LX-1180,LX-1600 and LX-100 resins for hydroxycobalamin were compared.The study found that D-85 resin had a large adsorption capacity and a high desorption rate.Then,the dynamic adsorption parameters of D-85 resin were further studied,the effects of loading rate,pH,pretreatment method on the adsorption capacity,and the influence of elution rate and pH on the desorption rate were analyzed,and the hydroxycobalamin extraction process was determined.The details were as follows:the hydroxycobalamin solution?pH 4.0?was loaded at a flow rate of 2BV/h,and the saturated adsorption capacity reached 398.57mg/g;then it was eluted with 60%ethanol solution?pH 4.0?at a flow rate of 1BV/h,and the desorption rate was 97.85%.After extraction,the concentration of hydroxycobalamin in the eluent reached 1219.2mg/L,which was 20.25 times its initial concentration.After drying,the content of hydroxycobalamin was 21.95%.Therefore,this process the process was simple in operation,pollution-free,and had application value.