Melanin biosynthesis in bacteria, regulation and production perspectives

Abstract

The production of black pigments in bacteria was discovered more than a century ago and related to tyrosine metabolism. However, their diverse biological roles and the control of melanin synthesis in different bacteria have only recently been investigated. The broad distribution of these pigments suggests that they have an important role in a variety of organisms. Melanins protect microorganisms from many environmental stress conditions, ranging from ultraviolet radiation and toxic heavy metals to oxidative stress. Melanins can also affect bacterial interactions with other organisms and are important in pathogenesis and survival in many environments. Bacteria produce several types of melanin through dedicated pathways or as a result of enzymatic imbalances in altered metabolic routes. The control of the melanin synthesis in bacteria involves metabolic and transcriptional regulation, but many aspects remain still largely unknown. The diverse properties of melanins have spurred a large number of applications, and recent efforts have been done to produce the pigment at biotechnologically relevant scales.

Microbial production of melanin and its various applications

“…THN then undergoes a series of reduction and dehydration reactions to form 1,8-dihydroxynaphthalene (DHN). The polymerization of DHN results in DHN-melanin as the final product (Plonka and Grabacka 2006 ; Eisenman and Casadevall 2012 ; Pavan et al 2020 ). Notably, both pathways can be found in bacteria and fungi.…”

Insoluble organic matter in chondrites: Archetypal melanin-like PAH-based multifunctionality at the origin of life?

“…For the purposes of this paper, the main focus will be on the properties of those melanins found at the lowest evolutionary levels that may be closer to the prebiotic precursors, especially those in bacteria and fungi. For exhaustive coverage of the topic the reader is referred to several recent reviews [206][207][208][209].…”

“…Black melanin pigments in bacteria play diverse biological roles, including protection from UV radiation, heavy metals and oxidative stress, and have been implicated in pathogenesis and survival in adverse environments (Fig. 9) [206].…”

Identification of Biomolecules Involved in the Adaptation to the Environment of Cold-Loving Microorganisms and Metabolic Pathways for Their Production

“…Melanins are a group of black pigments widely distributed in animals, plants, fungi and bacteria [56] (Figure 3). They are secondary metabolites made up of complex heterogeneous polymers of phenolic and/or indolic monomers [57].…”