Liquid extraction of low molecular mass organic acids and hydroxamate siderophores from boreal forest soil
Liquid extraction of low molecular mass organic acids and hydroxamate siderophores from boreal forest soil
复制标题
DOI：
10.1016/j.soilbio.2011.08.015
复制
发表时间：
2011-12-01
影响因子：
9.7
通讯作者：
Lundstrom, Ulla S.
中科院分区：
文献类型：
--
作者：
Ali, Tara;Bylund, Dan;Lundstrom, Ulla S.
低分子量有机酸(LMMOA)和羟胺酸铁载体(HS)是由微生物分泌的分子，以前在土壤溶液和培养物中发现过。菌根真菌可能参与树木的养分吸收过程和矿物风化过程。在这项研究中，取自土壤土O层和E层的土壤样品用10 mM磷酸二氢钾缓冲液在pH 7.2下提取。可变参数包括在提取缓冲液中添加甲醇，以及在提取过程中使用超声波或旋转摇动。测定了土壤浸出物中LMMOAs和HS的含量。用液-质联用(LC-MS)对土壤萃取物进行分析，并将提取结果与土壤样品离心法获得的土壤溶液样品的结果进行比较。在萃取缓冲液中加入甲醇可以显著提高萃取率，尤其是对O层样品。旋转摇动90min的样品比超声15min的产率略高，但提取时间的缩短使超声成为一个有吸引力的选择。在所测定的HSS中，所有样品中都含有铁霉素。最佳提取条件表明，柠檬酸和异柠檬酸分别是O层和E层中含量最丰富的有机酸。(C)2011爱思唯尔有限公司。保留所有权利。
Low molecular mass organic acids (LMMOAs) and hydroxamate siderophores (HS) are molecules secreted by microbes and have previously been found in soil solution and in cultures. Mycorrhizal fungi are suggested to be involved in the nutrient uptake processes of trees and weathering of minerals. In this study soil samples taken from the O and E horizons of a podzol were extracted with 10 mM potassium phosphate buffer at pH 7.2. Variable parameters included addition of methanol to the extraction buffer and the use of ultrasonication or rotary shaking during extraction. LMMOAs and HS content of the soil extracts were determined. Analysis of soil extracts were carried out by liquid chromatography mass spectrometry (LC-MS) and the extraction results compared to results for soil solution samples obtained by centrifugation of the soils sampled. The extraction yields were significantly increased by addition of methanol to the extraction buffer, especially for the O horizon samples. Rotary shaking of the samples for 90 min gave slightly higher yields than ultrasonication for 15 min but the reduction in extraction time makes ultrasonication an attractive option. Of the HSs determined, ferricrocin was found in all samples. Optimal extraction conditions showed citric acid and isocitric acid to be the most abundant organic acids in the O and E horizons, respectively. (C) 2011 Elsevier Ltd. All rights reserved.