title: Salmonella typhimurium and Escherichia coli dissimilarity: Closely related bacteria with distinct metabolic profiles.
abstract: Live attenuated strains of Salmonella typhimurium have been extensively investigated as vaccines for a number of infectious diseases. However, there is still little information available concerning aspects of their metabolism. S. typhimurium and Escherichia coli show a high degree of similarity in terms of their genome contents and metabolic networks. However, this work presents experimental evidence showing that significant differences exist in their abilities to direct carbon fluxes to biomass and energy production. It is important to study the metabolism of Salmonella to elucidate the formation of acetate and other metabolites involved in optimizing the production of biomass, essential for the development of recombinant vaccines. The metabolism of Salmonella under aerobic conditions was assessed using continuous cultures performed at dilution rates ranging from 0.1 to 0.67 h(-1), with glucose as main substrate. Acetate assimilation and glucose metabolism under anaerobic conditions were also investigated using batch cultures. Chemostat cultivations showed deviation of carbon towards acetate formation, starting at dilution rates above 0.1 h(-1). This differed from previous findings for E. coli, where acetate accumulation was only detected at dilution rates exceeding 0.4 h(-1), and was due to the lower rate of acetate assimilation by S. typhimurium under aerobic conditions. Under anaerobic conditions, both microorganisms mainly produced ethanol, acetate, and formate. A genome-scale metabolic model, reconstructed for Salmonella based on an E. coli model, provided a poor description of the mixed fermentation pattern observed during Salmonella cultures, reinforcing the different patterns of carbon utilization exhibited by these closely related bacteria.
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.
authors.forename: Cintia R
authors.initials: CR
authors.lastname: Sargo
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.
authors.forename: Gilson
authors.initials: G
authors.lastname: Campani
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.
authors.forename: Gabriel G
authors.initials: GG
authors.lastname: Silva
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.
authors.forename: Roberto C
authors.initials: RC
authors.lastname: Giordano
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.
authors.forename: Adilson J
authors.initials: AJ
authors.lastname: Da Silva
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Zangirolami
authors.affiliation: Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos, SP, 13565-905,, Brazil.|CEB-Centre of Biological Engineering, University of Minho, Campus De Gualtar, Braga, 4710-057,, Portugal.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Correia
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, Campus De Gualtar, Braga, 4710-057,, Portugal.
authors.forename: Eugénio C
authors.initials: EC
authors.lastname: Ferreira
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, Campus De Gualtar, Braga, 4710-057,, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Rocha
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D055442:Metabolome; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*; D014614:Vaccines, Synthetic / Q000096:biosynthesis
chemical_list: D003470:Culture Media; D014614:Vaccines, Synthetic; D005947:Glucose
keywords: Salmonella typhimurium; aerobic/anaerobic conditions; extracellular metabolomics