title: Bioreactor aeration conditions modulate growth and antigen expression during Erysipelothrix rhusiopathiae cultivation.
abstract: Erysipelothrix rhusiopathiae, the causative agent of swine erysipelas, was cultivated in a 5-L stirred and aerated bioreactor under different dissolved oxygen tensions (0%, 5%, and 30% of saturation) for evaluation of the influence of oxygen on cell growth as well as on the production of the main antigenic component of the vaccine against erysipelas, a 64-69 kDa protein (SpaA). The microorganism presented different growth profiles for different aeration conditions. However, at the end of the batch cultivations, similar cell concentrations were obtained under the studied conditions. In order to maximize biomass titers and antigen production, the microorganism was cultivated in fed-batch operation mode under aerobic conditions. Under this condition, there was a fivefold increase in biomass production in comparison to the results attained in batch cultivations. To follow up antigen expression, samples collected during batch cultivations were concentrated and treated with choline for antigen extraction. Antigen expression was then assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and by murine immunization tests. It was observed a direct influence of oxygen availability upon antigen expression, which is favored in the presence of oxygen. Analysis of the samples collected throughout the fed-batch process also revealed that antigen production is growth associated.
authors.affiliation: Departamento de Engenharia Química, Universidade Federal de São Carlos, Rod Washington Luís, São Carlos, SP, Brazil.
authors.forename: Adilson José
authors.initials: AJ
authors.lastname: da Silva
authors.forename: Alvaro
authors.initials: A
authors.lastname: de Baptista-Neto
authors.forename: Maria
authors.initials: M
authors.lastname: do Carmo Cilento
authors.forename: Roberto
authors.initials: R
authors.lastname: de Campos Giordano
authors.forename: Teresa Cristina
authors.initials: TC
authors.lastname: Zangirolami
mesh_terms: D000332:Aerobiosis; D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D001428:Bacterial Vaccines / Q000096:biosynthesis / Q000276:immunology; D019149:Bioreactors; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D004888:Erysipelothrix / Q000254:growth & development* / Q000378:metabolism*; D005260:Female; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D051379:Mice; D010101:Oxygen Consumption
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D003470:Culture Media; C114457:SpaA protein, Erysipelothrix rhusiopathiae; D019344:Lactic Acid; D005947:Glucose