Purification and Characterisation of a Sulphur Rich Melanin from Edible Mushroom Termitomyces albuminosus Heim

Author: mycolabadmin
2018-07-09
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Summary

This research characterized a unique type of melanin (a dark pigment) produced by an edible mushroom species. The melanin was found to have unusually high sulphur content, which may help protect the fungus during its life cycle. This basic research advances our understanding of natural pigments and their protective functions in organisms. Impacts on everyday life: – Provides insights into natural protective pigments that could inspire new UV-protective materials – Advances understanding of edible mushroom biochemistry and metabolism – Could lead to new applications in materials science and biotechnology – Helps explain how organisms protect themselves from environmental stress – May inspire development of new natural colorants or protective compounds

Background

Melanin biosynthesis is common in fungi, appearing as a secondary metabolite not essential for hyphal growth. Melanins are stable, amorphous polymers of phenolic compounds classified as eumelanins, pheomelanins and allomelanins. They help protect organisms from extreme environmental conditions like UV radiation, heat/cold, heavy metals and oxidants while providing cell wall rigidity. Despite their importance, many fundamental questions about melanin’s chemical structure and insolubility remain unanswered.

Objective

This study aimed to produce dark melanin-like pigment from pure culture of Termitomyces albuminosus under controlled conditions, purify it, verify its chemical identity as melanin, and characterize it structurally. This is the first report on melanin formation and characterization from Termitomyces species.

Results

The study successfully produced and characterized melanin from T. albuminosus culture. SEM revealed melanin nanoparticles of 400-100 nm size. Elemental analysis showed 54.6% C, 3.5% H, 2.4% N, 26.9% O, and notably high 12% S content. Spectroscopic analyses confirmed the identity as DOPA-type melanin with chemical modifications through oxidation and cysteinylation (pheomelanin) as indicated by the high sulphur content.

Conclusion

The study established the chemical identity of the dark pigment as a unique form of fungal melanin with unusually high sulphur content. While the exact structure remains difficult to fully elucidate, the incorporation of sulphur scaffold in Termitomyces melanin may play important functional roles in protecting the species during critical life cycle stages.

Published in:Mycology,
Study Type:Laboratory Research,
Source: 10.1080/21501203.2018.1494060