title: Pyomelanin production in Penicillium chrysogenum is stimulated by L-tyrosine.
abstract: From a tomb in Upper Egypt we isolated a strain of Penicillium chrysogenum that was capable of producing brown pigment in vitro when grown in a minimal salts medium containing tyrosine. We present evidence that this pigment is a pyomelanin, a compound that is known to assist in the survival of some micro-organisms in adverse environments. We tested type strains of Pe. chrysogenum, which were also able to produce this pigment under similar conditions. Inhibitors of the DHN and DOPA melanin pathways were unable to inhibit the formation of the pigment. Fourier transform IR analysis indicated that this brown pigment is similar to pyomelanin. Pyrolysis-GC/MS revealed the presence of phenolic compounds. Using LC/MS, homogentisic acid, the monomeric precursor of pyomelanin, was detected in supernatants of Pe. chrysogenum cultures growing in tyrosine medium but not in cultures lacking tyrosine. Partial regions of the genes encoding two enzymes in the homogentisic acid pathway of tyrosine degradation were amplified. Data from reverse-transcription PCR demonstrated that hmgA transcription was increased in cultures grown in tyrosine medium, suggesting that tyrosine induced the transcription.
authors.affiliation: 1Laboratory of Applied Microbiology, School of Engineering and Applied Sciences, Harvard University, 58 Oxford St., Cambridge, MA 02138, USA.
authors.forename: Archana
authors.initials: A
authors.lastname: Vasanthakumar
authors.affiliation: 1Laboratory of Applied Microbiology, School of Engineering and Applied Sciences, Harvard University, 58 Oxford St., Cambridge, MA 02138, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: DeAraujo
authors.affiliation: 2Getty Conservation Institute, Getty Center Drive, Los Angeles, CA 90049, USA.
authors.forename: Joy
authors.initials: J
authors.lastname: Mazurek
authors.affiliation: 2Getty Conservation Institute, Getty Center Drive, Los Angeles, CA 90049, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Schilling
authors.affiliation: 1Laboratory of Applied Microbiology, School of Engineering and Applied Sciences, Harvard University, 58 Oxford St., Cambridge, MA 02138, USA.
authors.forename: Ralph
authors.initials: R
authors.lastname: Mitchell
mesh_terms: D002853:Chromatography, Liquid; D003470:Culture Media / Q000737:chemistry; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004534:Egypt; D004783:Environmental Microbiology; D008401:Gas Chromatography-Mass Spectrometry; D013058:Mass Spectrometry; D008543:Melanins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D010408:Penicillium chrysogenum / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017550:Spectroscopy, Fourier Transform Infrared; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D003470:Culture Media; D004271:DNA, Fungal; D008543:Melanins; C023793:pyomelanin; D014443:Tyrosine