Optimization Of Fermentation,Extraction And Separation Process Of Hyaluronic Acid

Hyaluronic acid is a high molecular weight straight chain mucopolysaccharide,with unique molecular structure and rheological characteristics,and excellent moisture properties and viscoelastic properties,and no immunogenicity and toxicity.Hyaluronic acid is widely used in cosmetics,biological medicine and food industry.The production methods of hyaluronic acid are chemical synthesis,animal tissue extraction and microbial fermentation,but the fermentation is the main method in the industry.In this paper,the fermentation process and extraction and separation of hyaluronic acid from Streptococcus equi and ATCC39920 as the original strain were studied.Firstly,it studied the optimal seed medium for shaking flask.In the end,it gets the best seed medium.The result showed the optimal seed medium were as follows:2%soluble starch,1%yeast extract powder,0.2%K2HPO4,0.2%MgSO4.It has made the growth curve of seed shaking flask,and determined the optimal seed age.Secondly,it studied the optimal fermentation medium for shaking flask.In the end,it gets the best fermentation medium.The result showed the optimal fermentation medium were as follows:2%sucrose,2%yeast extract powder,0.2%MgSO4,0.13%K2SO4,0.62%Na2HPO4.The metabolic curve of fermentation shaking flask products was determined,and the optimal fermentation time was 24 h.Thirdly,it studied the fermentation process in the fermentation cylinder.After determining the best seed medium,fermentation medium and optimal age,the culturing was carried out in a 15 L fully automatic fermentation cylinder,and studied the carbon metabolism.The optimal initial sugar concentration was 5%,and the HA yield was 4.938 g/L.After that,it investigated the effect of constant speed sugar supplement about the HA yield,and the optimal rate of sugar supplement was 30 mL/h,the HA yield was 6.596 g/L.Finally,it studied the extraction process of the fermentation liquid hyaluronic acid.The separation and purification process of hyaluronic acid was determined.After a series of extraction and purification steps:pretreatment of fermentation broth,centrifugation,removal of bacteria,adsorption of activated carbon,removal of pigment,ultrafiltration concentration,ethanol precipitation,precipitation wash,vacuum freeze drying,and finally get the finished product.The final product yield was 83.5%,the protein content was 0.0016%,reaching the extraction yield was over 80%.