A single peer-reviewed methods study made fungal melanin directly measurable in soil using liquid chromatography. Chemical markers distinguished pigment types while tests with plant materials checked for interference. Peatland and organic forest layers contained more melanin than agricultural soils. More pigment accompanied higher carbon and nitrogen concentrations and larger amounts of dead fungal residues, without determining how long the pigment preserves carbon.
Sylwia Adamczyk and Bartosz Adamczyk developed a method to measure fungal melanin in a complex mixture of soil organics. Fungal cell walls contain pigments collectively called melanin. The single peer-reviewed methods study used liquid chromatography to separate chemical markers for different pigment types. Earlier genomic approaches showed fungi’s capacity to produce melanin rather than directly measuring the pigment retained in soil.[1]
The procedure combined acid pretreatment with alkaline oxidation, followed by chromatography and identity checks using mass spectrometry. The team tested synthetic melanins, laboratory-grown fungi and soils, alongside seeds, cones, roots, lignin and tannins. Plant materials did not produce markers specific to fungal allomelanin. By contrast, dye and infrared assays also responded to certain plant compounds other than melanin.[1]
Repeated measurements in the same run had relative standard deviations of 1.4 per cent for soil and 0.6 per cent for standards. The authors recommended checking recovery separately for each soil, because standards and mineral binding can affect concentration estimates.[1]
Allomelanin and eumelanin predominated in the soils, while pheomelanin was generally absent. Total melanin was highest in peatland and organic forest layers and lowest in agricultural soils. Higher concentrations accompanied more carbon and nitrogen, together with larger amounts of dead fungal residues. The relationship did not determine how long carbon persists in soil.[1]
