Abiotic Degradation of Lignified Cell Walls by Carbonate and Copper Salt

• Published in: Journal of agricultural and food chemistry Vol. 52; no. 4; pp. 816 - 822
• Main Authors: Durot, Nathalie, Pollet, Brigitte, Lapierre, Catherine, Kurek, Bernard
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 25-02-2004
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Carbonates - chemistry; Cell Wall - chemistry; Copper - chemistry; Food engineering; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Hydrogen-Ion Concentration; Life Sciences; Lignin - analysis; Lignin - chemistry; Potassium - chemistry; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; polysaccharides; Agricultural chemical product; Lignin; Vegetals; Wood; Phenolic acid; Pesticides; Transition metal; Pectin; Inorganic element; calcareous soils; Cell wall; Straw; Degradation; Soils; Chemical reaction; pectins; phenolic acids; Copper; Polysaccharide; Picea abies; Triticum aestivum; plant cell wall; lignin; transition metal
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf030132m

This study reports on the destructuration of Wheat straw and Spruce wood cell walls after maceration in potassium carbonate or sodium hydroxide at pH = 10 in the presence of copper acetate. The alkaline treatments had a predominant impact on the wheat straw cell wall components over copper acetate. Either K-carbonate or Na-hydroxide extracted from wheat straw a particular lignin fraction rich in condensed C−C linkages, leading to the unmasking of new ether-linked sub-structures in the cell wall. This unmasking was increased in the presence of copper salt but only in the nonextracted Wheat straw sample incubated in carbonate and not in the corresponding extractive-free sample. This difference was related to the leaching of compounds from the nonextracted cell wall, which could sustain oxidative activity of copper by hindering its precipitation into inactive hydroxide and/or carbonate species. In Spruce wood samples, copper salt was the principal factor impacting on the lignin structure over alkali alone. Its effect was, however, only detected at the level of C−C linked dimers. These results confirmed that unmasking of lignin sub-structures also occurred in Spruce wood, but probably through mechanisms different from that evidenced in Wheat straw. Keywords: Triticum aestivum; Picea abies; calcareous soils; lignin; polysaccharides; pectins; phenolic acids; plant cell wall; transition metal