title: Optimization of Vi capsular polysaccharide production during growth of Salmonella enterica serotype Typhi Ty2 in a bioreactor.
abstract: Vi capsular polysaccharide is synthesized during growth of Salmonella typhi Ty2 and is spontaneously released from the bacterial cells into the culture medium during culture. Vi production was dependent on cell growth and the greater the cell mass the greater the production of Vi. Using fed batch culture to optimize bacterial growth resulted is an increase in cell mass and consequently Vi production. The yield of Vi obtained in fed batch culture was 415 mgl(-1), which was over three times that, obtained in batch culture. A proportion of the Vi remained cell associated in the form of a capsule and at least part of this was released from the bacterial surface by sonication. The size of the Vi polysaccharide produced was consistently high and did not change during the different phases of bacterial growth. The synthesis of Vi was also dependent upon the media components and the fermentation conditions. The presence of high concentrations of glucose at the beginning of growth inhibited the production of Vi, particularly during the stationary phase. At a concentration of 400 mM sodium phosphate the synthesis of Vi was strongly inhibited.
authors.affiliation: Vaccine Development Section, Laboratory Sciences Division, International Vaccine Institute, Seoul National University Research Park, Kwanak-Gu, Seoul 151-818, Republic of Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Jang
authors.forename: Yeon Kyung
authors.initials: YK
authors.lastname: Yoon
authors.forename: Jeong Ah
authors.initials: JA
authors.lastname: Kim
authors.forename: Hyo Seung
authors.initials: HS
authors.lastname: Kim
authors.forename: So Jung
authors.initials: SJ
authors.lastname: An
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Seo
authors.forename: Changfa
authors.initials: C
authors.lastname: Cui
authors.forename: Rodney
authors.initials: R
authors.lastname: Carbis
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D049109:Cell Proliferation; D011135:Polysaccharides, Bacterial / Q000302:isolation & purification* / Q000378:metabolism*; D011786:Quality Control; D019779:Salmonella enterica / Q000502:physiology*
chemical_list: D011135:Polysaccharides, Bacterial; C054154:capsular polysaccharide, Salmonella