Process Optimisation for Increased Polysaccharide Yield of Neisseria Meningitidis (Serogroup W135) by Submerged Fermentation

摘要

Serogroup W135 polysaccharides from Neisseria meningitidis constitute a vaccine antigen against the disease caused by this bacterium. In the present study, a series of pilot scale experiments were carried out in a 300 L fermentor to enhance the final polysaccharide (PS) yield for industrial vaccine production. A three-step submerged fermentation technique significantly increased the production of Neisseria meningitidis serogroup W135 polysaccharides. Optimal conditions for polysaccharide production were as follows: ammonia nitrogen of 1.0 mg/mL, culture temperature of 36.5 ???°C, initial incubation concentration of 5????10 cfu-mL ?￠????1 and pH 7.0. The natural slow pH recovery of half an hour was considered the culture endpoint for the submerged fermentation, which provided a balance between polysaccharide quality and quantity. The highest PS yield reached 55 ????g/mL, and the obtained W135 polysaccharide satisfied the WHO criteria for suitable antigens for industrialized vaccine production by the strategies. To date, this is the first report on the efficient control and optimization of the industrial process of capsular polysaccharide production.