Metabolite and transcriptome analysis of Campylobacter jejuni in vitro growth reveals a stationary-phase physiological switch.
Campylobacter jejuni is a prevalent cause of food-borne diarrhoeal illness in humans. Understanding of the physiological and metabolic capabilities of the organism is limited. We report a detailed analysis of the C. jejuni growth cycle in batch culture. Combined transcriptomic, phenotypic and metabolic analysis demonstrates a highly dynamic 'stationary phase', characterized by a peak in motility, numerous gene expression changes and substrate switching, despite transcript changes that indicate a metabolic downshift upon the onset of stationary phase. Video tracking of bacterial motility identifies peak activity during stationary phase. Amino acid analysis of culture supernatants shows a preferential order of amino acid utilization. Proton NMR (1H-NMR) highlights an acetate switch mechanism whereby bacteria change from acetate excretion to acetate uptake, most probably in response to depletion of other substrates. Acetate production requires pta (Cj0688) and ackA (Cj0689), although the acs homologue (Cj1537c) is not required. Insertion mutants in Cj0688 and Cj0689 maintain viability less well during the stationary and decline phases of the growth cycle than wild-type C. jejuni, suggesting that these genes, and the acetate pathway, are important for survival.
Wright
John A
JA
Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
Grant
Andrew J
AJ
Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
Hurd
Douglas
D
Oxford Gene Technology, Begbroke Science Park, Sandy Lane, Yarnton, Oxford OX5 1PF, UK.
Harrison
Marcus
M
Oxford Gene Technology, Begbroke Science Park, Sandy Lane, Yarnton, Oxford OX5 1PF, UK.
Guccione
Edward J
EJ
Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK.
Kelly
David J
DJ
Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK.
Maskell
Duncan J
DJ
Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
D000085:Acetates / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D016123:Campylobacter jejuni / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology*; D015169:Colony Count, Microbial; D003470:Culture Media; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D009682:Magnetic Resonance Spectroscopy; D008858:Microscopy, Phase-Contrast; D018715:Microscopy, Video; D009068:Movement; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000085:Acetates; D001426:Bacterial Proteins; D003470:Culture Media