Isolation and characterization of melanin pigment from Pleurotus cystidiosus (telomorph of Antromycopsis macrocarpa)

Abstract

Melanins are enigmatic pigments that are produced by a wide variety of microorganisms including several species of bacteria and fungi. For more than 40 years, fungi have been known to produce pigments called melanins. Melanin pigment production by mushrooms was not intensively studied. The present study was carried out on isolation and characterization of melanin from an edible mushroom Pleurotus cystidiosus var. formosensis. The mushroom produced dark mucous mass of hyaline arthrospores on mycelium. The coremia exclusively produced dikaryotic arthrospores with the remnant of a clamp connection. Continuous cell extension and division in the coremium stipe supplied cells for arthroconidiation at the coremium apex, which is surrounded by a liquid droplet (coremioliquid). The black coloured coremea (conidia) were produced by Antromycopsis macrocarpa (anamorph of P. cystidiosus) when cultured on potato dextrose agar medium. The agar plate was incubated at continuous light illumination for high amount of pigment (coremea) production. The slimy layer of the coremea was extracted and partially purified by alkaline and acid treatment. The black pigment was confirmed as melanin based on UV, IR and EPR spectra apart from chemical analysis. This is the first report on characterization of melanin obtained from Pleurotus cystidiosus var. formosensis.

Purification and characterisation of a sulphur rich melanin from edible mushroom Termitomyces albuminosus Heim

“…Enochs et al (1993) described a standardised and effective test for the identification of melanin pigment by identifying the presence of stable population of organic free radical signal. The G -value of fungal melanin is reported to be 2.0012 (Selvakumar et al 2008). Termitomyces albuminosus melanin G -value is found to be somewhat higher which could be due to O-semiquinone free radicals.…”

“…UV-VIS spectrum was obtained in the range 190–750 nm using UV–VIS spectrophotometer (Shimadzu UV-2400) 0.1 mol/L NaOH as reference (Suryanarayanan et al 2004; Selvakumar et al 2008). A standard melanin spectrum was also obtained using Sepia officinalis melanin (Sigma, Aldrich Chemicals, India).…”

“…Studies on melanins in mushrooms are limited to edible mushrooms such as Pleurotus cystidious var. formosensis, P. australis , and P. purpureoolivaceus from which darkly pigmented arthroconidia forming black pigment on mycelium or basidiomata has been characterised (Selvakumar et al 2008). According to Mendoza et al (1979), the spore wall of Agaricus bisporous and Agaricus campestris contain 26–28% and 24–26% crude (dry weright cell wall) melanin.…”

Preparation of water-soluble melanin from squid ink using ultrasound-assisted degradation and its anti-oxidant activity

“…Melanin originates from different nature sources, such as Osmanthus fragrans seeds (Wang et al 2006), Pleurotus cystidiosusand (Selvakumar et al 2008), and silky fowl (Tu et al 2009), and has been reported to have excellent free radicals scavenge activity. Squid ink melanin is the most typical melanin usually used as melanin standard with strong free radical protection activities (Menon and Haberman 1977).…”

Some problems and errors in cytogenetic biodosimetry

“…It participates readily in processes of electron transfer and is an efficient free-radical scavenger [71][72][73]. Beverages such as tea, coffee and cocoa and foodstuffs such as grapes, bananas and edible fungi contain melanin-like pigments [74,75]. There have been reports that melanin could be among the causes for the phenomenon of increased survival of fungi growing on nuclear test sites after receiving multiple lethal radiation doses (after soil irradiation with 6400 Gy) [76].…”