Unveiling the molecular composition of the unextractable soil organic fraction (humin) by humeomics

被引:38
作者
Nebbioso, Antonio [1 ]
Vinci, Giovanni [1 ]
Drosos, Marios [1 ]
Spaccini, Riccardo [1 ]
Piccolo, Alessandro [1 ]
机构
[1] Univ Naples Federico II, Ctr Interdipartimentale Risonanza Magnet Nucl Amb, I-80055 Portici, Italy
关键词
Soil; Humin; Humeomics; GC-MS; Pyrolysis; NMR; Thermochemolysis; MATTER DIFFERENTIATION; PYROLYSIS; SUBSTANCES; ACID; TRANSESTERIFICATION; EXTRACTION; COMPONENTS; CHEMISTRY; SUBERIN; LIPIDS;
D O I
10.1007/s00374-014-0991-y
中图分类号
S15 [土壤学];
学科分类号
0903 ; 090301 ;
摘要
We applied humeomics to a soil unextractable humin fraction (HUM1) and its derived humin (HUM2) after removal of minerals by an HF/HCl treatment. Humeomics implies progressive separation and structural characterization of molecules released from complex humin matrices as (i) unbound, (ii) weakly ester-bound, (iii) strongly ester-bound, and (iv) ether-bound. Molecular characterization of fractions was achieved by GC-MS, thermochemolysis-GC-MS, and C-13-CPMAS-NMR. Both weight and chromatographic yields were higher for the clay-depleted HUM2 than those for HUM1, and this increased molecular detection in HUM2. Saturated and unsaturated alkanoic, alpha,omega-alkanedioic, hydroxyalkanoic acids, alkanols, and hydrocarbons were found in both HUM1 and HUM2. Abundant odd-C numbered n-alkanoic acids in unbound fractions indicated accumulation of free microbial metabolites, whereas plant-derived acids remained in fractions more tightly bound to the humin matrix. Unsaturated, n-alkanedioic, and hydroxyalkanoic acids were detected after hydrolysis of complex esters. The aromatic character in humin residues progressively increased with humeomics sequential steps, while alkyl and hydroxy-alkyl compounds were reduced. Humins contained similar components as a humic acid extracted from the same soil, implying that traditional humic pools differed in supramolecular arrangement rather than in molecular composition. The humeomic approach enables the determination of the molecular composition of humic matter and may improve knowledge of the structure-activity relations of organic matter in soil.
引用
收藏
页码:443 / 451
页数:9
相关论文
共 42 条
[1]   Distribution of structural units in humic substances as revealed by multi-step selective degradations and 13C-NMR of successive residues [J].
Almendros, G ;
Guadalix, ME ;
Gonzalez-Vila, FJ ;
Martin, F .
SOIL BIOLOGY & BIOCHEMISTRY, 1998, 30 (06) :755-765
[2]   STRUCTURAL STUDY ON THE SOIL HUMIN FRACTION - BORON TRIFLUORIDE-METHANOL TRANSESTERIFICATION OF SOIL HUMIN PREPARATIONS [J].
ALMENDROS, G ;
SANZ, J .
SOIL BIOLOGY & BIOCHEMISTRY, 1991, 23 (12) :1147-1154
[3]   Ester- and ether bond cleavage in immature kerogens [J].
Ambles, A ;
Grasset, L ;
Dupas, G ;
Jacquesy, JC .
ORGANIC GEOCHEMISTRY, 1996, 24 (6-7) :681-690
[4]  
Bento MFS, 2001, J ANAL APPL PYROL, V57, P45
[5]  
Bernards MA, 2002, CAN J BOT, V80, P227, DOI [10.1139/B02-017, 10.1139/b02-017]
[6]   The macromolecular aromatic domain in suberized tissue: A changing paradigm [J].
Bernards, MA ;
Lewis, NG .
PHYTOCHEMISTRY, 1998, 47 (06) :915-+
[7]   Soil organic matter chemistry in allophanic soils: a pyrolysis-GC/MS study of a Costa Rican Andosol catena [J].
Buurman, P. ;
Peterse, F. ;
Martin, G. Almendros .
EUROPEAN JOURNAL OF SOIL SCIENCE, 2007, 58 (06) :1330-1347
[8]   Thermogenic organic matter dissolved in the abyssal ocean [J].
Dittmar, Thorsten ;
Koch, Boris P. .
MARINE CHEMISTRY, 2006, 102 (3-4) :208-217
[9]   Separation of molecular constituents from a humic acid by solid-phase extraction following a transesterification reaction [J].
Fiorentino, G ;
Spaccini, R ;
Piccolo, A .
TALANTA, 2006, 68 (04) :1135-1142
[10]   Suberin - a biopolyester forming apoplastic plant interfaces [J].
Franke, Rochus ;
Schreiber, Lukas .
CURRENT OPINION IN PLANT BIOLOGY, 2007, 10 (03) :252-259