Metabolite and transcriptome analysis of Campylobacter jejuni in vitro growth reveals a stationary-phase physiological switch

• Published in: Microbiology (Society for General Microbiology) Vol. 155; no. 1; pp. 80 - 94
• Main Authors: Wright, John A, Grant, Andrew J, Hurd, Douglas, Harrison, Marcus, Guccione, Edward J, Kelly, David J, Maskell, Duncan J
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.01.2009; Society for General Microbiology
• Subjects: Acetates - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; Campylobacter jejuni; Campylobacter jejuni - genetics; Campylobacter jejuni - growth & development; Campylobacter jejuni - metabolism; Campylobacter jejuni - physiology; Colony Count, Microbial; Culture Media; Fundamental and applied biological sciences. Psychology; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Genetics; Growth, nutrition, cell differenciation; Magnetic Resonance Spectroscopy; Metabolism. Enzymes; Microbiology; Microscopy, Phase-Contrast; Microscopy, Video; Movement; Oligonucleotide Array Sequence Analysis - methods; Phenotype; Reverse Transcriptase Polymerase Chain Reaction; Metabolite; Campylobacteraceae; Transcriptome; Bacteria; Switching; Campylobacter jejuni; Stationary phase
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.021790-0

1 Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK 2 Oxford Gene Technology, Begbroke Science Park, Sandy Lane, Yarnton, Oxford OX5 1PF, UK 3 Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK Correspondence John A. Wright j.wright{at}eastman.ucl.ac.uk 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 ( 1 H-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. Abbreviations: 1 H-NMR, proton NMR; QRT-PCR, quantitative RT-PCR Present address: Division of Microbial Diseases, UCL Eastman Dental Institute, University College London, 256 Gray's Inn Road, London WC1X 8LD, UK. The microarray design and complete dataset from this study have been deposited in the ArrayExpress database ( www.ebi.ac.uk/arrayexpress ) with the accession numbers A-MEXP-1015 and E-MEXP-1436, respectively. Three supplementary tables listing genes significantly upregulated or downregulated during different phases of growth, genes grouped by cluster and profile by Short Time-series Expression Miner (STEM) analysis, and utilization data for amino acids, are available with the online version of this paper.