Quenching of QS-regulated pigments and bioluminescence by <i>S. delphini</i>.

<p><i>P. aeruginosa</i> (<b>A</b>), <i>S. marcescens</i> (<b>B</b>), <i>V. harveyi</i> (<b>C</b>) and <i>C. subtsugae</i> (<b>D</b>) were each co-cultivated with <i>S. aureus</i> (1) or <i>S. delphini</i> (2) for 24 h. Pyocyanin, which is excreted by <i>P. aeruginosa</i>, was determined in the supernatant at its absorption maximum A_{520 nm}. Prodigiosin, which is cell wall bound in <i>S. marcescens</i>, was ethanol-extracted from the cell pellet and determined at its absorption maximum A_{534 nm}. Bioluminescence of <i>V. harveyi</i> was intensified by aeration before measuring in a bioluminescence reader. Violacein from <i>C. subtsugae</i> was quantitatively extracted with butanol and determined at its absorption maximum A_{585 nm}.