The Nw-162 Strain Of Streptococcus Zooepidemicus Hyaluronic Acid Fermentation And Extraction Process Of Research

This paper studied on the optimization of the technology of fermentation and separation and extraction of hyaluronic acid by .streptococcus zooepidemics NW- 162. The production of HA by streptococcus zooepidemics NW-I 62 was studied under flask culture and fed-batch culture conditions, the optimal conditions for HA production were: A 36-hour fed-batch fermentation yield a final HA concentration of 0.747g/L, in a medium containing yeast extract, peptone and beef extract as the best nitrogen source and glucose as the best carbon source, with an initial PH of 7.2, at a temperature of 36 C and consuming 6% glucose, which featured periodical glucose feeding, a different dissolved oxygen concentration (DOC) and PH-stat method, high DOC promoted cell growth, while lower DOC facilitated HA accumulation, and optimum PH value was different for cell growth of 7.2 and HA accumulation of 6.8. The paper also carried out a comparative study on the technology of separation and extraction of HA in the fermented liquid. The results were as follows: (1) The method that HA was treated by ethanol of 2.5x volume for 20 hours turned out to be the most economic and efficient. (2) Zymolysis combined with deproteinization by chloroform was better than deproteinization by chloroform for several times in yield and purity of HA. (3) HA with purity of 71.1 60/o was obtained by the fermentation with cetylpyridinium chloride (CPC). Furthermore, the physical and chemical properties of HA were determined in the experiment.