Fungal melanin-based electrospun membranes for heavy metal detoxification of water

Microbial production of melanin and its various applications

“…Melanin can act as metal chelators, which can be employed in environmental applications. By incorporating fungal melanin with other polymers such as polycaprolactone and polyurethane, the melanin-based composites can remove up to 94% Pb(II) in water systems (Tran-Ly et al 2020 ). Although there are a lot of studies reporting the potential applications of melanin, they are mostly in the developmental stage and have not yet been commercialized.…”

“…Moreover, melanization is considered a survival strategy for many organisms inhabiting unfavorable environmental conditions. Owing to the multifunctionality of the pigment, it has been known to serve as: (a) an antioxidant and radical scavenger (Ju et al 2011 ; Le Na et al 2019 ), (b) a photo-protector that efficiently absorbs and dissipates solar radiation in the form of heat (d’Ischia et al 2015 ), (c) an absorber that chelates metals and binds organic compounds (Karlsson and Lindquist 2016 ; Tran-Ly et al 2020 ) and (d) an organic semiconductor (Bothma et al 2008 ). Besides these functions, melanin is considered eco-friendly and biocompatible since it is naturally synthesized by most organisms.…”

Recent advances in novel remediation processes towards heavy metals removal from wastewaters

“…Armillaria cepistipes (Empa 655) was used by the researchers in developing reliable biosorbent filtration membrane for heavy metal remediation. The result of using this natural filtration membrane shows 90% of removal capacity of Pb, Ni, Cd, and Cr ions from wastewater (Tran-Ly et al, 2020).…”

Direct and Indirect Neurotoxic Potential of Metal/Metalloids in Plants and Fungi Used for Food, Dietary Supplements, and Herbal Medicine

“…Fungi also bisorb and sequester heavy metals via melanin, a negatively charged hydrophobic pigment formed by the polymerization of indolic and phenolic compounds. Experiments with melanin extracted from Armillaria cepistipes (Ringless Honey Mushroom) revealed a differential metal affinity, namely Pb 2+ > Cr 3+ > Ni 2+ > Cd 2+ > Zn 2+ > Ca 2+ —with an extreme preference for Pb 2+ (80% removal) over the essential metals (0% and 12% removal for Ca 2+ and Zn 2+ , respectively) [ 46 ]. Fungal melanin production can be both constitutive and facultative, production increasing according to environmental stressors, such as UV radiation, drying, high concentrations of salts, heavy metals, and radionuclides [ 47 ].…”