Characterization of an autostimulatory substance produced by Escherichia coli

D. H. Weichart, D. B. Kell

    Research output: Contribution to journalArticlepeer-review

    Abstract

    The recovery of dilute populations of stationary phase cells of Escherichia coli was studied using an automatic growth analyser. The addition of 30% supernatant from 2-d-old stationary phase cells of the organism reproducibly shortened the apparent lag times by 22-57.5%, depending on the age of the inoculum. True lag times, as determined by colony counts, of stationary phase cells were reduced by supernatant addition by 41-62%. The growth-stimulating substance was characterized and partly purified from supernatants: the active material was shown to be dialysable, heat-stable, acid- and alkali-stable and protease-resistant. Extraction with ethyl acetate or ion-exchange resins was not successful, but the active material could be quantitatively extracted with ethanol after saturation with salt. It is concluded that the active substance is a small, non-proteinaceous, non-ionic organic molecule. Separation of extracts by HPLC indicated that the stimulatory substance is weakly hydrophobic and has retention times similar to those of uracil. So far, however, the exact chemical identity of the active substance has not been elucidated.
    Original languageEnglish
    Pages (from-to)1875-1885
    Number of pages10
    JournalMicrobiology
    Volume147
    Issue number7
    Publication statusPublished - 2001

    Keywords

    • Growth stimulation
    • Intercellular signalling
    • Lag phase

    Fingerprint

    Dive into the research topics of 'Characterization of an autostimulatory substance produced by Escherichia coli'. Together they form a unique fingerprint.

    Cite this