Study On Hyaluronic Acid Fermentation Conditions Of Streptococcus Zooepidemicus

In this paper, the strain of Streptococcus zooepidemicus was used to study on the hyaluronic acid fermentation conditions.Firstly, fermentation conditions were optimized in shake-flask.Secondly, fermentation medium was optimized in shake-flask by RSM and found the best concentration of the two key factors was the glucose and yeast extract.Finally, experiments were made to confirmate fermentation conditions of hyaluronic acid in small fermentor.The results were as follows:1、In order to enhance the hyaluronic acid yield by streptococcus zooepidemicus fermentation. controlling temperature, pH, fermentation time and liquid volume were tested.The results showed that the bacteria amount and the hyaluronic acid yield on the condition of pH7.0,24h fermentation time and40%liquid volume was the maximum value,and in the36℃have most bacteria amount, in37℃have the highest hyaluronic acid yield.2、The fermentation medium of hyaluronic acid was optimized in shake flask by Plaekett-Burman design and response surface methodology (RSM), and found that the key factors which influence the hyaluronic acid production were glucose and yeast extract and the best concentration were55.78g/L and23.43g/L respectively.By optimizing the medium,the production of hyaluronic acid was increased and the experimental value was consistent with the predicted one.3、The monofactorial test of hyaluronic acid fermentation was conducted on the condition of different ventilation,stir speeds and fermentation temperature in5L fermentor. The production of hyaluronic acid was significantly increased on the condition of3L/min ventilation,200r/min stir speed and36℃in18h fermentation,37℃among18-28h fermentation.