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Structural Characteristics of a Fungal Melanin and a Soil Humic Acid
Author(s) -
Schnitzer M.,
Chan Y. K.
Publication year - 1986
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1986.03615995005000010013x
Subject(s) - hydrolysis , chemistry , acid hydrolysis , humic acid , melanin , sugar , chemical structure , amino acid , organic chemistry , biochemistry , fertilizer
A melanin produced by Hendersonula toruloidea and a soil humic acid were characterized by a number of chemical (elemental and functional group analyses, carbohydrate content, amino acid, amino sugar, and NH 3 analyses) and spectroscopic methods (IR and 13 C NMR) before and after 6 M HCl hydrolysis. The following distinct differences were observed between the two materials: (i) phenolic components were prominent in the untreated and hydrolyzed melanins but not in the corresponding soil humic acids (HA); (ii) the melanin contained more complex unidentified N than did the soil HA; and (iii) following hot acid hydrolysis, the melanin was more aliphatic but considerably less aromatic than the soil HA. Hot acid hydrolysis, by removing practically all of the proteinaceous materials and carbohydrates from the two materials, made it possible to focus on the structural chemistry of the residual materials.