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Features of bacterial growth and polysaccharide production of Streptococcus pneumoniae serotype 14
Author(s) -
Massaldi Hugo,
Bessio M. Inés,
Suárez Norma,
Texeira Esther,
Rossi Silvina,
Ferreira Fernando
Publication year - 2010
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1042/ba20090218
Subject(s) - polysaccharide , streptococcus pneumoniae , serotype , molecular mass , microbiology and biotechnology , conjugate , bacterial growth , streptococcaceae , size exclusion chromatography , bacterial capsule , biology , chemistry , food science , bacteria , biochemistry , chromatography , enzyme , antibiotics , mathematical analysis , genetics , mathematics , virulence , gene
The effect of several cultivation conditions on the kinetics of bacterial growth and polysaccharide production of Streptococcus pneumoniae serotype 14 was studied. The presence in the supernatant of serotype‐specific CPS (capsular polysaccharide) during growth was followed by size‐exclusion HPLC and, in parallel, confirmed by using a specific latex reagent. The agitation level did not affect the production behaviour, whereas pH maintenance above 6 strongly enhanced both growth and CPS production throughout the cultivation period in flasks. Production of high‐molecular‐mass polysaccharide was found to be maximal between 5 and 6 h of cultivation, at the end of the exponential phase. By laser light scattering, 90% of this purified CPS product showed a M w (molecular mass) range from 350 to 1500 kDa, with an average M w of 921 kDa. Extending the culture to 24 h gave rise to a clear shift of the M w distribution of the polysaccharide to values lower than 100 kDa. These findings may have strong implications for the large‐scale manufacture of the polysaccharide and the associated conjugate vaccine.