توليد رنگدانه‌ ملانين ميكروبي، خالص‌سازي، بهينه‌سازي و بررسي خصوصيات فيزيكوشيميايي و بيولوژيكي آن

Production of microbial melanin pigment, purification, optimization an‎d investigation of its physicochemical an‎d biological properties

زيست شناسي سلولي مولكولي و ميكروبيولوژي

Microbial melanin has emerged as a sustainable alternative to synthetic dyes due to its biocompatibility an‎d medicinal properties. In this study, the production, optimization, an‎d investigation of the biological an‎d physicochemical properties of melanin obtained from the yeast Hortaea werneckii were examined. YPG culture medium was used as the optimal medium, an‎d a novel an‎d cost-effective medium, "Natural composition P," was employed for microbial melanin production. The growth of the yeast an‎d its macroscopic an‎d microscopic characteristics were eva‎luated in both culture media. Identification an‎d characterization of the produced melanins were performed using solubility tests, UV-Vis spectroscopy, H NMR spectroscopy, an‎d FTIR spectroscopy. Biological assays of the melanins included eva‎luation of antioxidant activity, anti-melanoma activity through molecular docking studies an‎d toxicity testing on the A375 melanoma cell line, an‎d investigation of the effect of the produced melanins on the proliferation of human osteoblast MG63 cells. Finally, to enhance melanin production, optimization of melanin production in both culture media was carried out using OFAT an‎d RSM methods. The produced melanins were insoluble in most organic solvents but soluble in sodium hydroxide solution, confirming their identity as melanin. The maximum absorption of melanin in YPG an‎d Natural composition P media was observed at wavelengths of 208 an‎d 203 nm, respectively. H NMR spectroscopy showed the presence of aliphatic, aromatic, an‎d oxygen- an‎d nitrogen-bound protons in both melanins, an‎d FTIR spectra confirmed the presence of carboxylic, hydroxyl, amine, an‎d aromatic functional groups in both melanins. The antioxidant activity of YPG an‎d Natural composition P melanins was 89% an‎d 93.5%, respectively, at a concentration of 10 mg/mL. In the anti-melanoma activity study, after confirming the anti-melanoma properties of melanin by molecular docking studies, the toxicity effect of the produced melanins on the A375 melanoma cell line showed that the best result was related to melanin produced in Natural composition P with a toxicity of 50.27% at a concentration of 31 µg/mL. Both melanins increased the proliferation of human osteoblast MG63 cells at most concentrations. Optimization of production increased melanin production in YPG an‎d Natural composition P media to 3.635 an‎d 3.515 g/L, respectively. In this study, the production an‎d optimization of melanin from the yeast Hortaea werneckii in YPG an‎d Natural composition P culture media were successfully carried out. The results showed that the produced melanins have strong antioxidant properties, desirable anti-melanoma activity, an‎d the potential to proliferate human osteoblast cells. Optimization of culture conditions led to increased melanin production an‎d confirmed the high potential of this method for biological an‎d industrial applications. This study, for the first time, successfully demonstrated the growth of Hortaea werneckii yeast an‎d melanin production in Natural composition P medium.

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