Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment ...

Polydopamine (PDA) generated by the oxidative self-polymerization of dopamine shows great potential for surface modification. Observed PDA nanostructures are nanoparticles and thin films. The formation mechanism of PDA is still unclear; thus, the manipulation of PDA nanostructures is a big challenge. In this study, we first demonstrated that folic acid shows a dramatic effect on the PDA nanostr...

The relationship between cell pigmentation and radiosensitivity was investigated in two selected human melanoma cell lines with different melanin content (mixed type: eumelanin and pheomelanin, and pheomelanotic phenotypes). The same study was also done after stimulation of melanogenesis (1) by addition of the melanin precursor l-tyrosine to each of the cell lines separately and (2) by irradiat...

Two cases of neurocutaneous melanosis are presented. MR showed hyperintense areas in the brain on short-repetition-time/short-echo-time sequences, compatible with intraparenchymal melanin deposits. No leptomeningeal abnormality was seen.

Ten isolates of Aureobasidium pullulans were screened for the highest production of pullulan and minimal melanin production from Fayoum Governorate, Egypt. The optimum conditions for continuous culture were studied; temperature was 24°C, while pH 5.0, and agitation speed was at 500 rpm, while the aeration rate was 2.5 vvm and the best flow rate was 1 L/ 24 h. The maximum production of pullulan ...

Traits used in communication, such as colour signals, are expected to have positive consequences for reproductive success, but their associations with survival are little understood. Previous studies have mainly investigated linear relationships between signals and survival, but both hump-shaped and U-shaped relationships can also be predicted, depending on the main costs involved in trait expr...

The control mechanisms and information content of melanin-based color signals in birds have generated much recent interest and controversy among evolutionary biologists. Initial experimental studies on this topic manipulated coarse metrics of an individual's condition (i.e. food intake, disease state) and failed to detect significant condition-dependence of melanin ornament expression. However,...