Tannic acid reduces recovery of water-soluble carbon and nitrogen from soil and affects the composition of Bradford-reactive soil protein
Tannic acid reduces recovery of water-soluble carbon and nitrogen from soil and affects the composition of Bradford-reactive soil protein
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DOI：
10.1016/j.soilbio.2007.07.022
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发表时间：
2008
影响因子：
9.7
通讯作者：
J. Halvorson;Javier M. Gonzalez
中科院分区：
文献类型：
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作者：
J. Halvorson;Javier M. Gonzalez
单宁是植物来源的多酚化合物，其沉淀蛋白质，与金属结合并与其他化合物络合。单宁酸，或其他酚类化合物的溶液，被添加到土壤样品中，以确定它们是否会影响可溶性土壤碳（WSC）或氮（WSN）的恢复或影响布拉德福德反应性土壤蛋白（BRSP）的提取和组合物，与球囊霉素。单宁酸-C加入水没有完全从样品中回收，回收的总净WSC和WSN的量减少，表明形成不溶性复合物。相比之下，非单宁酚类物质如没食子酸或没食子酸甲酯对WSC或WSN的提取几乎没有影响，而由单宁酸衍生的简单没食子单宁，1，2，3，4，6-五-O-没食子酰-d-葡萄糖（PGG），对提取的抑制作用最大。BRSP中的C和N浓度增加时，土壤样品用单宁酸或PGG提取前，一个程序，包括高压灭菌处理。与0-5cm深度相比，10- 20 cm深度的增加最大。伴随着这些是在465和665 nm的吸光度比（E4/E6比）的BRSP提取物表明形成更大或更重的分子下降。与此相反，C和N组成的冻干BRSP不受影响，甚至略有减少时，单宁酸或PGG添加到提取过程后的BRSP提取液。我们的结论是，一些单宁可以减少不稳定的土壤C和N的溶解度，至少暂时和不可预测的响应与酚类物质，布拉德福德测定不应该依赖于量化池或组合物的土壤蛋白质，如球囊霉素。
Tannins are plant-derived polyphenolic compounds that precipitate proteins, bind to metals and complex with other compounds. Solutions of tannic acid, or other phenolic compounds, were added to soil samples to determine if they would affect recovery of soluble soil carbon (WSC) or –nitrogen (WSN) or influence the extraction and composition of Bradford-reactive soil protein (BRSP), associated with glomalin. Tannic acid-C added with water was not completely recovered from samples and the amount of total net WSC and WSN recovered was reduced, suggesting formation of insoluble complexes. By comparison, non-tannin phenolics like gallic acid, or methyl gallate, had little effect on extraction of WSC or WSN while a simple gallotannin derived from tannic acid, 1,2,3,4,6-penta-O-galloyl-d-glucose (PGG), inhibited extraction most. The C and N concentrations in BRSP increased when soil samples were treated with tannic acid or PGG before extraction, a procedure that includes autoclaving. Increases were greatest in the 10–20cm compared to 0–5cm depth. Accompanying these were declines in the ratio of absorbance at 465 and 665nm (E4/E6 ratio) of BRSP extracts suggesting formation of larger or heavier molecules. In contrast, C and N composition in lyophilized BRSP was unaffected or even slightly reduced when tannic acid or PGG were added to the BRSP extract solution after the extraction process. We conclude that some tannins can reduce the solubility of labile soil C and N, at least temporarily and given unpredictability of response associated with phenolic substances, the Bradford assay should not be relied on to quantify pools or composition of soil proteins like glomalin.