title: Pyomelanin is produced by Shewanella algae BrY and affected by exogenous iron.
abstract: Melanin production by Shewanella algae BrY occurred during late- and (or) post-exponential growth in lactate basal salts liquid medium supplemented with tyrosine or phenylalanine. The antioxidant ascorbate inhibited melanin production but not production of the melanin precursor homogentisic acid. In the absence of ascorbate, melanin production was inhibited by the 4-hydroxyphenylpyruvate dioxygenase inhibitor sulcotrione and by concentrations of Fe >or= 0.38 mmol L(-1). These data support the hypothesis that pigment production by S. algae BrY was a result of the conversion of tyrosine or phenylalanine to homogentisic acid, which was excreted, auto-oxidized, and self-polymerized to form pyomelanin. Pyomelanin production by S. algae BrY may play an important role in the biogeochemical cycling of Fe in the environment.
authors.affiliation: Environmental Biotechnology Section, Savannah River National Laboratory, Building 999W, Aiken, SC 29808, USA. charles.turick@srnl.doe.gov
authors.forename: Charles E
authors.initials: CE
authors.lastname: Turick
authors.forename: Frank
authors.initials: F
authors.lastname: Caccavo
authors.forename: Louis S
authors.initials: LS
authors.lastname: Tisa
mesh_terms: D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D003512:Cyclohexanones / Q000378:metabolism; D006713:Homogentisic Acid / Q000378:metabolism; D007501:Iron / Q000378:metabolism / Q000494:pharmacology*; D008543:Melanins / Q000096:biosynthesis* / Q000378:metabolism; D008698:Mesylates / Q000378:metabolism; D020592:Shewanella / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D003512:Cyclohexanones; D008543:Melanins; D008698:Mesylates; C028063:melanin precursors; C023793:pyomelanin; C079906:sulcotrione; D007501:Iron; D015111:4-Hydroxyphenylpyruvate Dioxygenase; D006713:Homogentisic Acid