title: Capsular polysaccharide production by Streptococcus pneumoniae serotype 1: from strain selection to fed-batch cultivation.
abstract: Streptococcus pneumoniae is a human pathogen largely transmitted by aerosols. Vaccines are the main strategy against this pathogen, and the capsular polysaccharide (PS) is its major antigen. S. pneumoniae serotype 1 is associated with large outbreaks and epidemics of invasive diseases. The aims of this work were to screen serotype 1 strains to identify the best PS1 producer, evaluate three peptones for PS1 production, investigate the effects of culture medium components using a design of experiments (DoE), a statistic tool for optimization, and propose a new medium/cultivation strategy. After flask cultivation of nine strains, two that produced high PS1 and biomass values were chosen for further evaluation in the bioreactor, and ST595/01 was chosen as the best PS1 producer strain. Among the peptones tested (Casamino acids, Soytone, and Phytone), the highest PS1 production (298 mg/L) was reached with Phytone. Next, DoE (2(4-1)) was performed to evaluate the effects of yeast extract (YE), Phytone, L-asparagine (Asn), and L-glutamine (Gln), yielding the following results: Phytone presented positive effects (p < 0.05) for maximum production of biomass, PS1, acetate, and lactate; YE showed positive effects for biomass and acid production (p < 0.05); Gln exerted a minor positive effect on PS1 yield factor on glucose (p < 0.1); and Asn presented only an effect on acetate production (p < 0.1). Hence, a new culture medium was formulated based on Phytone, YE, and glucose, and batch and fed-batch cultivations were evaluated. The fed-batch cultivation showed almost 2 times the biomass and 2.5 times the PS1 production as the batch culture, and 8-10 times higher PS1 production than has been previously reported.
authors: Laboratório de Bioprocessos, Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, SP, 05503-900, Brazil.
authors: Bruno Vitorio
authors: BV
authors: Marthos
authors: Laboratório de Bioprocessos, Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, SP, 05503-900, Brazil.
authors: Anne Letícia Silva
authors: AL
authors: Ferri
authors: Laboratório de Bioprocessos, Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, SP, 05503-900, Brazil.
authors: Douglas Borges
authors: DB
authors: de Figueiredo
authors: Departamento de Engenharia Química, Universidade Federal de São Carlos, Rodovia Washington Luís km 235, São Carlos, SP, 13565-905, Brazil.
authors: Teresa Cristina
authors: TC
authors: Zangirolami
authors: Laboratório de Bioprocessos, Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, SP, 05503-900, Brazil. viviane.goncalves@butantan.gov.br.
authors: Viviane Maimoni
authors: VM
authors: Gonçalves
mesh_terms: D061249:Batch Cell Culture Techniques; D003470:Culture Media / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D012641:Selection, Genetic; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D003470:Culture Media; D011135:Polysaccharides, Bacterial
keywords: Capsular polysaccharide production; Design of experiments; Fed-batch cultivation; Peptone selection; Pneumococcus; Strain screening