Optimization Of Crypthecodinium Cohnii Medium And Mutation Breeding

Docosahexaenoic acid(Docosahexaenoic acid,DHA)belongs to the omega-3-series polyunsaturated fatty acid(PUFAs),which is also a polyunsaturated fatty acid necessary for the human body.DHA can promote the development of children’s brain,protect eyesight,prevent cardiovascular and cerebrovascular diseases and other physiological functions.Meanwhile,DHA has been widely used in food,feed and medicine.The disadvantages of fish oil as a traditional source of DHA are increasingly prominent,while the Crypthecodinium cohnii is a relatively ideal type of DHA producing bacteria,with high DHA content and less other unsaturated fat,which is beneficial to the purification and industrialization of the application.In this study,the separation and purification of Crypthecodinium cohnii were mainly used in the method of dilution separation,solid plate coating and cloth marking separation.It is used to preserve the Crypthecodinium cohnii,using solid liquid bidirectional preservation,liquid secondary preservation,low temperature glycerin preservation and inclined surface preservation,etc.A molecular biological identification was performed on the CCMP316,which was identified as the Crypthecodinium cohnii.The genome size of Crypthecodinium cohnii was estimated to be about 3005.64Mb using the BD FAC Symphony A5 flow cytometer.Secondly,the ultrasonic breaking method was used to extract the oil,which was optimized for the ultrasonic time,the output power,the extraction solvent and the liquid ratio.The results showed that the oil yield was 42.78%and 10.46%higher than 32.22%before optimization.The culture medium was optimized of Crypthecodinium cohnii by single factor experiment and response surface experiment.The results showed that glucose,yeast powder and sodium acetate were the significant factors.After optimization,the concentration of glucose,yeast powder and sodium acetate was 25.31 g/L,2.5 g/L and 4.25 g/L,and the yield of DHA was 2.14g/L under optimal conditions,and 10.71%higher than before optimization.Finally,the ultraviolet mutagenesis,chemical mutagenesis(NTG)and ARTP mutagenesis were carried out.With iodine acetic acid and malonic acid as screening agent,build the vanillin phosphate,the method of rapid determination of oil content selection mutation algae strains,3 mutant strains were algae strains respectively offers UZ-3,NZ-11,AZ-14,compare the three strains mutation algae strains,get the optimal mutation algae strains AZ-14,algae strains for mutations AZ-14 for genetic stability research.