Hyaluronic Acid Biosynthesis And Purification

The paper related to a novel medium using core starch as primary carbon source, in which the strain of hyaluronic acid-producing Streptococcus zooepidemicus NJUST01 reproduced 60 generations continuously at 35癈. A comparison was made between the first and the 60th generation. The 60th colonies had no obvious difference with the first one in morphology as well as the yield level and the molecular weight of the hyaluronic acid produced by both. The optimal starch medium comprises starch 1.7% (wt/vol, the same as follow), yeast extract 2.0%, K2HPO4 1.0%, KH2PO4 1.0%, MgSO4 0.5%, pH 7.0, which was shaking at 35癈 for 18 hours until exponential growth phase was reached. The paper tested the effect of different factors to the final fermentation, such as MgSO4, inorganic compound, C/N, additive, inoculum volume, fermentation time, oxygen demand. The optimal final fermentation comprises starch 4.0%, yeast extract 1.0%, K2HPO4 1.0%, KH2PO4 1.0%, MgS04 0.5%, CaCO3 1.0%, MnSO4 0.06%, (NH4)2SO4 0.06%, pH 7.0, which was shaking at 37 C for 36 hours in the speed of 250 rpm. Automatic temperature and pH control were used.Hyaluronic acid was isolated from fermentation suspension. The process involved extraction with water, precipitation by ethanol, purification with cetyl-pyridinium salt. The yields were 3.5g/L, the molecular weight were 2.047 X 105Da.The paper observed the effect of antibiotic to Streptococcus zooepidemicus, when hyaluronic acid was added into the medium. As a result, the action of antibiotic to the tested bacteria was increase 1 - 1.5 times compared with the common medium without hyaluronic acid.