Polysaccharide production of Neisseria meningitidis (Serogroup C) in batch and fed-batch cultivations

Accumulation of organic acids in cultivations of Neisseria meningitidis C

“…Other aspects, such as polysaccharide formation, either associated to growth or not, nitrogen consumption and its assimilation by the cell, glucose consumption kinetics, as well as the relationship between polysaccharide and glucose concentration in batch and fed-batch processes had earlier been investigated by the authors [2][3][4]27]. Most of the results of polysaccharide production by N. meningitidis serogroup C listed in Table 2 are better than those obtained batch-wise by Carty et al, who reported a maximum polysaccharide concentration of 0.16 g l À1 after 22 h of cultivation, under constant aeration and agitation conditions, as a consequence of oxygen-limited cell growth [6].…”

“…A previous study reported average polysaccharide molar mass in the range 400-500 kDa, gel chromatography partition coefficient (K d ) lower than 0.3 and recovery rate (percentage of polysaccharide recovered before reaching K d =0.5) higher than 84% [4], which means that the product satisfies all the criteria for an antigen for vaccine preparation [12,36,37].…”

“…HCl . H 2 O, 2.00 g dialyzed yeast extract, 1.23 g MgSO 4 . 7H 2 O, 5.00 g glucose, and whose pH was adjusted to 7.4 with 5 N NaOH solution.…”

“…The content of one ampoule containing 6.3·10 9 viable cells of the meningococcal strain, maintained at À70°C in 0.5 ml of the medium of Greaves [16], was streaked out onto two agar slant tubes [25] and incubated at 35°C for 18-20 h in a candle jar (5-10% CO 2 ). The cells from each slant tube were resuspended in the liquid medium of Frantz [11] that contained (per liter) 1.60 g L-glutamic acid, 6.00 g NaCl, 4.67 g Na 2 HPO 4 . 7H 2 O, 1.25 g NH 4 Cl, 0.09 g KCl, 0.02 g L-cystein .…”

“…The fed-batch process has recently been tested with success [4]. However, alteration of the process conditions simultaneously influenced the consumption of substrate, the formation of polysaccharide and the release of undesired byproducts such as organic acids.…”