Koch Stella Marie, Freidank-Pohl Carsten, Siontas Oliver, Cortesao Marta, Mota Afonso, Runzheimer Katharina, Jung Sascha, Rebrosova Katarina, Siler Martin, Moeller Ralf, Meyer Vera
Radiation Biology Department, Aerospace Microbiology Research Group, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany.
Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany.
Front Microbiol. 2023 Jul 20;14:1233740. doi: 10.3389/fmicb.2023.1233740. eCollection 2023.
Melanins are complex pigments with various biological functions and potential applications in space exploration and biomedicine due to their radioprotective properties. Aspergillus niger, a fungus known for its high radiation resistance, is widely used in biotechnology and a candidate for melanin production. In this study, we investigated the production of fungal pyomelanin (Pyo) in by inducing overproduction of the pigment using L-tyrosine in a recombinant Δ mutant strain (OS4.3). The Pyo pigment was characterized using three spectroscopic methods, and its antioxidant properties were assessed using a DPPH-assay. Additionally, we evaluated the protective effect of Pyo against non-ionizing radiation (monochromatic UV-C) and compared its efficacy to a synthetically produced control pyomelanin (Pyo). The results confirmed successful production of Pyo in through inducible overproduction. Characterization using spectroscopic methods confirmed the presence of Pyo, and the DPPH-assay demonstrated its strong antioxidant properties. Moreover, Pyo exhibited a highly protective effect against radiation-induced stress, surpassing the protection provided by Pyo. The findings of this study suggest that Pyo has significant potential as a biological shield against harmful radiation. Notably, Pyo is synthesized extracellularly, differing it from other fungal melanins (such as L-DOPA- or DHN-melanin) that require cell lysis for pigment purification. This characteristic makes Pyo a valuable resource for biotechnology, biomedicine, and the space industry. However, further research is needed to evaluate its protective effect in a dried form and against ionizing radiation.
黑色素是具有多种生物学功能的复杂色素，由于其辐射防护特性，在太空探索和生物医学领域具有潜在应用价值。黑曲霉是一种以高抗辐射性著称的真菌，广泛应用于生物技术领域，也是黑色素生产的候选菌株。在本研究中，我们通过在重组Δ突变菌株（OS4.3）中使用L-酪氨酸诱导色素过量产生，研究了 中真菌脓性黑色素（Pyo）的产生。使用三种光谱方法对Pyo色素进行了表征，并使用DPPH测定法评估了其抗氧化性能。此外，我们评估了Pyo对非电离辐射（单色UV-C）的防护效果，并将其功效与合成生产的对照脓性黑色素（Pyo）进行了比较。结果证实通过诱导过量产生成功在 中生产了Pyo。光谱方法表征证实了Pyo的存在，DPPH测定法表明其具有强大的抗氧化性能。此外，Pyo对辐射诱导的应激表现出高度的防护作用，超过了Pyo提供的保护。本研究结果表明，Pyo作为一种抵御有害辐射的生物屏蔽具有巨大潜力。值得注意的是，Pyo是在细胞外合成的，这与其他需要细胞裂解进行色素纯化的真菌黑色素（如L-DOPA-或DHN-黑色素）不同。这一特性使Pyo成为生物技术、生物医学和航天工业的宝贵资源。然而，需要进一步研究以评估其干燥形式对电离辐射的防护效果。
