These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Characterization of melanin-overproducing transposon mutants of Pseudomonas putida F6.
    Author: Nikodinovic-Runic J, Martin LB, Babu R, Blau W, O'Connor KE.
    Journal: FEMS Microbiol Lett; 2009 Sep; 298(2):174-83. PubMed ID: 19624744.
    Abstract:
    Two melanin-overproducing Pseudomonas putida F6 mutants were generated using transposon (Tn5) mutagenesis. Mutants were disrupted in a transcriptional regulator (TR) and a homogentisate 1,2-dioxygenase (HDO) gene. Colonies of mutant F6-TR overproduced a black pigment on solid medium. The same mutant (F6-TR) had a 3.7-fold higher tyrosinase activity compared with the wild-type strain when induced with ferulic acid. However in tyrosine uptake assays whole cells of the mutant strain F6-TR consumed eight times less tyrosine compared with the wild-type strain. Mutant F6-HDO produced a diffusible red pigment into the growth medium. Pigment production by mutant F6-HDO is sixfold higher than the wild-type strain. The biomass yield of mutant F6-HDO grown on tyrosine as the sole source of carbon and energy was 1.2-fold lower than the wild-type strain. While the growth of the wild-type strain was completely inhibited by 5 min of exposure to UV light (254 nm) both mutant strains showed survival rates >30%. Mutant F6-HDO was able to tolerate higher concentrations of hydrogen peroxide (H(2)O(2)) exhibiting 1.5 times smaller zones of inhibition at 10 mM H(2)O(2) compared with mutant F6-TR and the wild-type strain. The pigments produced by all strains were purified and confirmed to be melanins.
    [Abstract] [Full Text] [Related] [New Search]