Melanins are natural biopolymers that are known to contribute to different biological processes and to protect organisms from adverse environmental conditions. During the past decade, melanins have attracted increasing attention for their use in organic semiconductors and bioelectronics, drug delivery, photoprotection and environmental bioremediation. Although considerable advances in these fields have been achieved, real-world applications of melanins are still scarce, probably due to the limited and expensive source of natural melanin. Nevertheless, recent biotechnological advances have allowed for relatively large-scale production of microbial melanins, which could replace current commercial melanin. In this review, we first describe different melanin sources and highlight the advantages and disadvantages of each production method. Our focus is on the microbial synthesis of melanins, including the methodology and mechanism of melanin formation. Applications of microbial melanins are also discussed, and an outlook on how to push the field forward is discussed.

中文翻译：

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黑色素的微生物产生及其各种应用

黑色素是已知的天然生物聚合物，有助于不同的生物过程并保护生物体免受不利环境条件的影响。在过去的十年中，黑色素因其在有机半导体和生物电子学、药物输送、光保护和环境生物修复中的应用而受到越来越多的关注。尽管在这些领域取得了相当大的进展，但黑色素在现实世界中的应用仍然很少，这可能是由于天然黑色素的来源有限且价格昂贵。尽管如此，最近的生物技术进步已经允许相对大规模地生产微生物黑色素，这可以取代目前的商业黑色素。在这篇综述中，我们首先描述了不同的黑色素来源，并强调了每种生产方法的优缺点。我们的重点是黑色素的微生物合成，包括黑色素形成的方法和机制。还讨论了微生物黑色素的应用，并讨论了如何推动该领域向前发展的前景。