Initiation of the flexirubin biosynthesis in Chitinophaga pinensis

Bacteria from the Bacteroidetes phylum are known producers of the chemotaxonomic relevant flexirubins. These orange pigments comprise a non-isoprenoid aryl-polyene carboxylic acid esterified with a dialkylresorcinol. Herein, we report a gene cluster from Chitinophaga pinensis encoding the biosynthesis of the polyene moiety and the biochemical characterization of a tyrosine ammonia-lyase and a 4-coumarate-CoA ligase responsible for the initiation of the polyene biosynthesis. Additionally, the flexirubin of C. pinensis was characterized by a combination of feeding experiments, high-performance liquid chromatography tandem mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry.