Botany and Microbiology Department, Faculty of Science, Al-Azhar University (Girls Branch), Cairo, Egypt.
Drug Radiation Research Department, Egyptian Atomic Energy Authority, National Center for Radiation Research and Technology (NCRRT), Cairo, Egypt.
Microb Cell Fact. 2024 Feb 26;23(1):68. doi: 10.1186/s12934-024-02335-y.
Owing to the growing need for natural materials in different fields, studying melanin production from biological sources is imperative. In the current study, the extracellular melanin pigment was produced by the fungus Curvularia soli AS21 ON076460. The factors that affect the production of melanin were optimized by the Plackett-Burman design (P-BD). The effect of gamma irradiation on melanin productivity was investigated. The maximum melanin yield (3.376 mg/L) was elicited by a stimulus of gamma irradiation at 1.0 kGy. The results evoked that, Curvularia soli AS21 ON076460 melanin exhibited excellent antimicrobial activity against all tested bacteria and fungi. Klebsiella pneumoniae ATCC 13883 and P. digitatum were mostly affected by melanin registering the inhibition zone diameters of 37.51 ± 0.012 and 44.25 ± 0.214 mm, respectively. Moreover, Curvularia soli AS21 ON076460 melanin indicated a significant antiviral efficacy (77% inhibition) of Herpes simplex virus (HSV1). The melanin pigment showed antioxidant activities with IC of 42 ± 0.021 and 17 ± 0.02 µg/mL against DPPH and NO, respectively. Melanin had cytotoxic action against human breast cancer and skin cancer cell lines (Mcf7and A431) as well as exerting a low percentage of cell death against normal skin cell lines (Hfb4). Melanin was effective in wound management of human skin cells by 63.04 ± 1.83% compared with control (68.67 ± 1.10%). The novelty in the study is attributed to the possibility of using gamma rays as a safe method in small economic doses to stimulate melanin production from the fungi that have been isolated. In summary, melanin produced from fungi has significant biological activities that encourage its usage as a supportive medical route.
由于对不同领域天然材料的需求不断增长，研究生物来源的黑色素生产势在必行。在本研究中，真菌 Curvularia soli AS21 ON076460 产生了细胞外黑色素色素。通过 Plackett-Burman 设计（P-BD）优化了影响黑色素生产的因素。研究了伽马辐射对黑色素生产力的影响。在 1.0 kGy 的伽马辐射刺激下，黑色素产量达到最大值（3.376 mg/L）。结果表明，Curvularia soli AS21 ON076460 黑色素对所有测试的细菌和真菌均表现出优异的抗菌活性。肺炎克雷伯菌 ATCC 13883 和 P. digitatum 受黑色素影响最大，抑菌圈直径分别为 37.51 ± 0.012 和 44.25 ± 0.214 mm。此外，Curvularia soli AS21 ON076460 黑色素对单纯疱疹病毒（HSV1）表现出显著的抗病毒功效（77%抑制）。黑色素色素显示出抗氧化活性，对 DPPH 和 NO 的 IC 分别为 42 ± 0.021 和 17 ± 0.02 µg/mL。黑色素对人乳腺癌和皮肤癌细胞系（Mcf7 和 A431）具有细胞毒性作用，对正常皮肤细胞系（Hfb4）的细胞死亡率较低（仅 17%）。与对照（68.67 ± 1.10%）相比，黑色素对人皮肤细胞的伤口管理有效，达到 63.04 ± 1.83%。本研究的新颖之处在于，使用伽马射线作为一种安全的方法，在小剂量经济剂量下刺激从已分离的真菌中生产黑色素的可能性。总之，真菌产生的黑色素具有重要的生物学活性，鼓励将其用作支持性医疗途径。
