Research On Group Y Meningococcus Fermentation Techniques

Meningitis is a kind of acute respiratory epidemic around the world caused by Neisseria meningitidis infection. Polysaccharides, membrane proteins and lipopolysaccharides are the main immune components of N. meningitids. N. meningitids can be classified to serogroup A, B, C, D, H,I,K, L,29E,W135,X,Y and Z.90%meningitis is due to serogroup A, B, C, W135and Y. Meningitis spreads fast, with high morbidity, mortality and serogroups floating. So vaccination is the best choice to prevent and control the diseaseTo obtain high yield of antigen composition-capsule polysaccharide from N. meningitids, fermentation and extraction technology were further developed. The first step was optimization of mediums and the parameters for fermentation, including inoculation quantity, pH value, temperature, cultivation time and dissolved oxygen level. Using the Orthogonal experiment method with evaluation of the quantity and quality of the polysaccharide yield, No.4meduim was selected and the parameters for fermentation was fermentation for9hours at pH7.0±0.2,36.5℃and60%dissolved oxygen. The important parameters for getting high quantity and quality of the polysaccharide were also developed. Using phenolic extraction for4times to remove the polysaccharide impurities, nucleic acid and protein could increase the productivity of the polysaccharide from N. meningitids.Finely, we assessed the representative and stability of selected parameters and screening the application of the selected parameters for consecutive batches repeat. The successful development of these methods would benefit for vaccine production and quality improvement, cost reduction of the Meningitis polysaccharides combination vaccine.