Premium
Properties and Decomposition and Binding Action in Soil of “Humic Acid” Synthesized by Epicoccum nigrum
Author(s) -
Martin J. P.,
Richards S. J.,
Haider K.
Publication year - 1967
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/sssaj1967.03615995003100050015x
Subject(s) - chemistry , humic acid , hydrolysis , benzoic acid , toluene , acid hydrolysis , decomposition , phenols , organic chemistry , nuclear chemistry , fertilizer
Epicoccum nigrum cultured in a glucose‐asparagine or glucose peptone medium synthesized a “humic acid” in yields of 2 to 6g from 15 l of medium. The fugnus “humic acid” and the humic acid fraction from leonardite used for comparison were both highly resistant to decomposition in soil and significantly improved soil aggregation and hydraulic conductivity at 0.1 to 0.5% concentrations. The carbon content ranged from 53 to 59% and the Nitrogen of most samples from 6 to 8.5. As the pH of the nutrient medium at termination of incubation increased, the nitrogen content of the humic acid fraction increased. Total acidity, COOH groups, phenolic OH groups, exchange capacity at different pH values, and molecular weights were all within the ranges reported for humic acids of soils and peats. Following reductive degradation with sodium amalgam and acidification to pH 1.0, ether extractable substances equivalent to 15 to 20% of the acid hydrolyzed humic acid were recovered. Chromatographic analysis of the ether extract separated 14 phenols including orcinol, orsellinic acid, 2, 4‐dihydroxy toluene, 2, 4‐dihydroxy‐benzoic acid, 3, 5‐dihydroxybenzoic acid, 2, 4, 5‐trihydroxy toluene, and 2, 3, 5‐trihydroxy toluene. From 30 to 48% of the nitrogen in the humic acid was released by proteases or hydrolysis with HCl.