BACTERIAL CAPSULAR POLYSACCHARIDE YIELD ENHANCEMENT BY ADDITION OF DEFOAMING AGENTS

摘要

The instant invention provides significant improvement in bacterial capsular polysaccharide yield at fermentation harvest stage, particularly Neisseria meningitidis capsular polysaccharides by gradual addition of an antifoam agent alongwith an optimal feed solution from log phase onwards. Specifically, antifoam increases optical density of the culture thereby resulting in higher capsular polysaccharide yield of about 2 to 2.5 gm/L at fermentation harvest stage wherein polysaccharide obtained has optimal average molecular weight of about 800KDa to about 1200KDa and has minimum load of contaminants like proteins and nucleic acid. The antifoam agent of the present invention was found to be bifunctional such that it increased the polysaccharide productivity as well as resulted in effective defoaming thereby making said fermentation process suitable for further scale-up.