background: there is a growing demand for mass production of shikalkin (a natural pigment consisted of shikonin and alkannin) due to its increasing applications in cosmetics, pharmaceutical and nutrition industries. the root of iranian arnebia euchroma produces shikalkin. the promising capability of this plant for shikalkin production has already been demonstrated in cell culture studies. objec...

the present study is designed to evaluate the application of a simple method for rapid identification of malassezia furfur among other malassezia spp. based on production of a brownish-red pigment and its diffusion into the medium containing l-tryptophan as a sigle source of nitrogen.  91 strains of malassezia (20% m. furfur , 2% m. sympodialis , 5% m. obtosa and 73% m. globosa ) isolated from ...

Duerre, John A. (University of North Dakota, Grand Forks), and Patrick J. Buckley. Pigment production from tryptophan by an Achromobacter species. J. Bacteriol. 90:1686-1691. 1965.-A microorganism was isolated from the soil near the University of North Dakota. Biochemical and morphological characteristics indicated that this organism would best be classified as a member of the family Achromobac...

PURPOSE We tested for protection of blue light-exposed A2E-containing retinal pigment epithelial (RPE) from damage through the implementation of polycarbonate filters containing varying levels of a pigment that absorbs short wavelength light. METHODS Human adult RPE cells (ARPE-19) that had accumulated synthesized A2E were exposed to either a light line delivered from a tungsten halogen sourc...

When a fish or a reptile changes color, it is because of the movement of tiny pigment granules in specialized skin cells called melanophores. These cells have hundreds of membrane-bound pigment granules, or melanosomes, which can be aggregated at the center of the cell or dispersed throughout the cytoplasm. When the melanosomes are aggregated the animal appears lighter, and as they disperse the...

In a previous paper [1] we discussed biliverdin IXa as an intermediate of phycocyanobilin biosynthesis (also compare [2—4]). The experiments involved the incubation of red algae of the species Cyanidium caldarium III-D-2 with the tetrapyrrole precursor 5-aminolevulinic acid. After 2—3 days incubation we observed as a main product a rather polar blue pigment of an as yet unknown structure in the...

C-phycocyanin, a natural blue-colored pigment-protein complex was explored as a novel photosensitizer for use in low-level laser therapy under 625-nm laser illumination. C-phycocyanin produced singlet oxygen radicals and the level of reactive oxygen species (ROS) were raised in extended time of treatment. It did not exhibit any visible toxic effect in the absence of light. Under 625-nm laser ir...

The genetically well-known strain Streptomyces coelicolor A3(2) produces the pH indicator (red/blue) antibiotic actinorhodin, but not all the "blue pigment" produced by this strain is actinorhodin. When the organism was subjected to various nutrient limitations (ammonium, nitrate, phosphate, or trace elements), and also during growth cessation caused by a relatively low medium pH, blue pigment ...

Objective(s): Pyocyanin is a blue-greenish redox-active pigment, produced by Pseudomonas aeruginosa, with a wide range of biological and biotechnological applications. Pyocyanin biosynthesis is regulated by the quorum-sensing (QS) system in which the expression of QS genes and QS-controlled virulence genes may be affected by serum as a complex medium. In the current study, effects of adult bovi...