AUTHOR=Devescovi Giulia , Kojic Milan , Covaceuszach Sonia , Cámara Miguel , Williams Paul , Bertani Iris , Subramoni Sujatha , Venturi Vittorio 

TITLE=Negative Regulation of Violacein Biosynthesis in Chromobacterium violaceum

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00349

DOI=10.3389/fmicb.2017.00349

ISSN=1664-302X

ABSTRACT=<p>In <italic>Chromobacteium violaceum</italic>, the purple pigment violacein is under positive regulation by the <italic>N</italic>-acylhomoserine lactone CviI/R quorum sensing system and negative regulation by an uncharacterized putative repressor. In this study we report that the biosynthesis of violacein is negatively controlled by a novel repressor protein, VioS. The violacein operon is regulated negatively by VioS and positively by the CviI/R system in both <italic>C. violaceum</italic> and in a heterologous <italic>Escherichia coli</italic> genetic background. VioS does not regulate the CviI/R system and apart from violacein, VioS, and quorum sensing regulate other phenotypes antagonistically. Quorum sensing regulated phenotypes in <italic>C. violaceum</italic> are therefore further regulated providing an additional level of control.</p>