Natural Science Forum / Biology / Microbiology / February 2007

Hi to all.....
Chris the pigment that you found in the Bacillus megaterium medium is
often melanin that was secreted by a yeast.
read this:
FEMS Microbiol Lett. 2004 Oct 1;239 (1):187-93 15451118
Blastomyces dermatitidis produces melanin in vitro and during
infection.
[My paper] Joshua D Nosanchuk , David van Duin , Piyali Mandal ,
Philip Aisen , Alfred M Legendre , Arturo Casadevall
Melanin is made by several important pathogenic fungi and is
implicated in the pathogenesis of a number of mycoses. This study
investigates whether the thermally dimorphic fungal pathogen
Blastomyces dermatitidis produces melanin. Using techniques developed
to study melanization in other fungi, we demonstrate that B.
dermatitidis conidia and yeast produce melanin in vitro and that yeast
cells synthesize melanin or melanin-like pigment in vivo. Melanization
reduced susceptibility to amphotericin B, but not to itraconazole or
voriconazole. Since melanin is an important virulence factor in other
pathogenic fungi, this pigment may affect the pathogenesis of
blastomycosis.
Mesh-terms: Amphotericin B, pharmacology; Animals; Antifungal Agents,
pharmacology; Blastomyces, growth & development; Blastomyces,
metabolism; Blastomyces, pathogenicity; Blastomycosis, microbiology;
Dog Diseases, microbiology; Dogs; Humans; Lung, metabolism; Lung,
microbiology; Melanins, biosynthesis; Microbial Sensitivity Tests;
Research Support, U.S. Gov't, P.H.S.;

from:http://lib.bioinfo.pl/auth:Mandal,P
but Chris does the yeast really lives symbiotically with B.
megaterium? or pollution?