Characterization of polysaccharide production of haemophilus influenzae Type b and its relationship to bacterial cell growth
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Published on: December 17, 2015
Mickie Takagi1, Joaquin Cabrera-Crespo, Júlia Baruque-Ramos
1Laboratório de Fermentação, Instituto Butantan, Centro de Biotecnologia, Av. Vital Brasil, 1500, CEP 05503-900, São Paulo, Brazil. mtakagi@butantan.gov.br
Abstract:
Haemophilus influenzae type b (Hib) causes invasive infections in infants and young children. Vaccines consisting of Hib capsular polysaccharide (polymer of ribosylribitol phosphate [PRP]) conjugated to a protein are effective in the prevention of such infections. The production of capsular polysaccharide type b was studied in three cultivation conditions: single, glucose pulse, and repeated batch. Specific polysaccharide production (Yp/x) was calculated for all experiments, showing the following values: 67 (single-batch cultivation), 71 (glucose pulse), 75 (repeated-batch cultivation, first batch), and 87 mg of PRP/g of dry cell weight (DCW) (repeated-batch cultivation, second batch). Biomass concentration reached approximately 1.8 g of DCW/L, while polysaccharide concentration was about approximately 132 mg/L in the three fermentation runs. Polysaccharide synthesis is associated with cell growth in all studied conditions as established by Kono's analysis and Luedeking-Piret's model.
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