ABSTRACT
Capsular polysaccharide, extracted from microorganism cultivations, is the principal antigen for elaboration of vaccine against the disease caused by Neisseria meningitidis serogroup C. The final protein content allowed in this vaccine is 1 (per cent). In order to find a relationship between nitrogen consumption and cell growth, including polysaccharide production, and cell nitrogen content, cultivations were carried out in an 80 liters bioreactor (total capacity), under the following conditions: Frantz medium; temperature of 35ºC; air flow of 5L/min (0.125vvm); agitation frequency of 120 rpm and vessel pressure of 6 psi (k(L)a=0.07min(-1).Concentrations of biomass, total polysaccharide, cellular nitrogen, residual organic and inorganic nitrogen in the medium were measured during cultivation. From five cultivations carried out under the same conditions, a mean cell nitrogen percentage of 12.6(per cent)(w/w) in respect to the dry biomass was found. The inorganic nitrogen in the medium did not change significantly along the cultivation time, whereas the organic nitrogen consuption was linearly related to cell growth, with constant yeield factors (average of 8.44). Polysaccharide production kinetics followed the cell growth kinetics until the beginning of the stationary growth phase. A supplemental polysaccharide production was observed until the end of cultivation, but without cell nitrogen absorption. Thus, the results indicate that polysaccharide is produced in two phases, being the first one biomass formation followed by non-associated to growth. /
Subject(s)
Polysaccharides , Polysaccharides, Bacterial , Bacterial Vaccines , Neisseria meningitidis , In Vitro Techniques , Bacterial Proteins/analysis , Bacterial Proteins/isolation & purification , Culture Media , Serologic Tests/methodsABSTRACT
Polysaccharide of N. meningitidis serogroup C constitutes the antigen for the production of the specific vaccine against this serogroup. The production kinetics of polysaccharide (serogroup C) was studies in five cultivations carried out in an 80 L fermenter (total capacity), under the following process conditions: Frantz medium; temperature 35§C; air flow 5 L.min-1 (o.125 vvm); agitation frequency 120 rpm and vessel pressure 6 psi. Global yeld factors and ield coefficients were calculated. It was observed two distinguished polysaccharide production phases: growth associated and a growth non-associated. The cell productivity was about 0.11 (g drymass. L -1.h-1) and polysaccharide productivity near 7.0 (mg polysac. L-1. h-1)(AB)