Ciencias Agrarias >
Instituto de Recursos Naturales y Agrobiología Sevilla (IRNAS) >
(IRNAS) Artículos >
Open Access item Degradative studies on a soil humin fraction-sequential degradation of inherited humin
González-Vila, Francisco Javier
|Abstract:||Degradation products of soil humin preparations from three different soil types were studied.
Inherited humin was isolated by ultrasonic treatment and densimetry of the heavy fraction of soil, and
purified by treatment with dilute alkali and acid and exhaustive lipid extraction. These purified humins,
which represented 10-26% of the total soil C (34-55% of total alkali-insoluble humified C), were degraded
with potassium persulfate followed by alkaline permanganate oxidation. The degradation products
obtained (identified by GC-MS as methyl derivatives) were fatty acids, dicarboxylic aliphatic acids,
benzenecarboxylic acids, phenolic acids and alkanes.
An unexpectedly high proportion of polymethylene compounds (mainly fatty acids) were observed in
the humins of the three soils, in both loosely and strongly associated forms. It is considered that these
aliphatic chains are stable humin constituents, physically or chemically associated with a highly oxidized,
demethoxylated and disordered matrix entrapping a significant proportion of non-polar compounds.
Some of the aliphatic components seem to be inherited from cuticular waxes of higher plants, but it is
tentatively suggested that during the microbial reworking of lignins the lipid polymers were altered, then
contributing to the formation of humin.|
|Description:||8 pages, 3 figures, 3 tables, 23 references.|
|Appears in Collections:||(IRNAS) Artículos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.