Optimization of fermentation media for the production of higher yield capsular polysaccharide by Streptococcus pneumoniae serotype 22F using integrated statistical designs.

The Streptococcus pneumoniae is known to cause various forms of pneumonia viz. bronchitis, otitis media, septicaemia, and meningitis. The pathogenicity of S. pneumoniae is proportional to the thickness of capsular polysaccharide (CPS). Therefore, it is the key molecule for the vaccine development. The optimization of fermentation media and conditions for the growth of S. pneumoniae and volumetric CPS yield are crucial for efficient and cost-effective CPS production. Further, the regulatory organization-ICH recommends the development of process through quality by design (QbD) approach. Therefore, current study employs integrated approach viz. OFAT (one factor at-a-time), Plackett-Burman and RSM design to systematically evaluate the effects of various media components on CPS yield. The key factors such as carbon, nitrogen source, macro/micro-nutrients and fermentation conditions were studied. The optimized media resulted in highest reported CPS yield of 819 and 1860 mg/L using batch and fed-batch fermentation respectively. This study presents a well-designed strategy utilizing the QbD approach for the optimization of growth media and fermentation conditions, that enhance the final growth as well CPS productivity by S. pneumoniae serotype 22F. The same approach can be used for optimization of media for other serotypes of S. pneumoniae as well used for multivalent vaccine production.