title: Accumulation of organic acids in cultivations of Neisseria meningitidis C.
abstract: Aiming at the industrial production of serogroup C meningococcal vaccine, different experimental protocols were tested to cultivate Neisseria meningitidis C and to investigate the related organic acid release. Correlations were established between specific rates of acetic acid and lactic acid accumulation and specific growth rate, during cultivations carried out on the Frantz medium in a 13 l bioreactor at 35 degrees C, 0.5 atm, 400 rpm and air flowrate of 2 l min(-1). A first set of nine batch runs was carried out: (1) with control of dissolved oxygen (O2) at 10% of its saturation point, (2) with control of pH at 6.5, and (3) without any control, respectively. Additional fed-batch or partial fed-batch cultivations were performed without dissolved O2 control, varying glucose concentration from 1.0 to 3.0 g l(-1), nine of which without pH control and other two with pH control at 6.5. No significant organic acid level was detected with dissolved O2 control, whereas acetic acid formation appeared to depend on biomass growth either in the absence of any pH and dissolved O2 control or when the pH was kept at 6.5. Under these last conditions, lactic acid was released as well, but it did not seem to be associated to biomass growth. A survey of possible metabolic causes of this behavior suggested that N. meningitidis may employ different metabolic pathways for the carbon source uptake depending on the cultivation conditions.
authors.affiliation: Universidade de São Paulo (EACH-USP), Av. Arlindo Bettio, 1000, 03828-000, São Paulo, Brazil. jbaruque@usp.br
authors.forename: Júlia
authors.initials: J
authors.lastname: Baruque-Ramos
authors.forename: Haroldo
authors.initials: H
authors.lastname: Hiss
authors.forename: Attilio
authors.initials: A
authors.lastname: Converti
authors.forename: Viviane Maimone
authors.initials: VM
authors.lastname: Gonçalves
authors.forename: Isaías
authors.initials: I
authors.lastname: Raw
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000592:standards*; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism*; D038542:Neisseria meningitidis, Serogroup C / Q000254:growth & development* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism
chemical_list: D019344:Lactic Acid; D019342:Acetic Acid; D010100:Oxygen