| 摘要 |
Disclosed is a process for reducing the protein content and preserving the capsular polysaccharide content in a complex cellular Streptococcus pneumoniae lysate broth prior to purification, the process comprising the steps of: (a) growing a selected S. pneumoniae serotype in a soy-based medium, which includes: (i) inoculating a first container containing the soy-based medium with seed stock of the selected serotype, and incubating the first container until growth requirements are met, (ii) inoculating a second container containing the soy-based medium with the culture from step (i) while maintaining a stable pH and temperature in the second container, and (b) lysing with a detergent the bacterial cells produced in step (a), thereby producing a lysate containing soluble proteins, cell debris, nucleic acids and polysaccharide; (c) agitating the cellular lysate for a time sufficient to assure complete lysis and polysaccharide release; (d) lowering the pH of the cellular lysate to less than 5.5 to precipitate out the detergent and most of the soluble proteins; (e) holding the solution and precipitate formed in step (d) without agitation for a time sufficient to allow settling of the precipitate; and (f) processing the solution and precipitate by centrifugation and/or filtration, whereby the capsular polysaccharide in solution is preserved and the soluble protein is effectively reduced.
|
