Quantification of 2,4-diacetylphloroglucinol produced by fluorescent Pseudomonas spp. in vitro and in the rhizosphere of wheat
Quantification of 2,4-diacetylphloroglucinol produced by fluorescent Pseudomonas spp. in vitro and in the rhizosphere of wheat
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DOI：
10.1128/aem.63.3.951-955.1997
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发表时间：
1997-03-01
影响因子：
4.4
通讯作者：
Thomashow, LS
中科院分区：
文献类型：
--
作者：
Bonsall, RF;Weller, DM;Thomashow, LS
广谱抗生素2，4-二乙酰基间苯三酚（Phl）是荧光假单胞菌（Pseudomonasspp.）生物防治多种植物病害的主要决定因素。开发了一种易于从肉汤和琼脂培养物以及植物根际环境中分离和定量Phl的方案。在酸性pH下用乙酸乙酯提取Phl适用于体外和原位来源。在酸性pH下添加用80%丙酮的初始提取步骤在消除极性有机土壤组分如腐殖酸和富里酸方面是非常有效的，所述极性有机土壤组分可干扰通过高效液相色谱法进行的PhI检测。一次提取的土壤中Phl的回收率平均为54.6%，第二次提取增加了另外6.1%。这些产率显著高于通常用于从土壤中提取极性酚类化合物的几种标准方案所获得的产率。Phl首次从原始土壤的根际环境中分离，通过应用荧光假单胞菌Q2-87和Phl高产菌株Q2-87，（pPHL 5122）对小麦种子的转化率分别为2.1和2.4 μ g Phl/g根加根际土壤;从生长在沙诺粉壤土中的小麦中分离出的Phl/g根加根际土壤分别为0.37和1.3 μ g。然而，当Phl的量根据细胞密度计算时，Q2-87（pPHL 5122）在Ritzville粉砂壤土和Shano粉砂壤土中产生的抗生素分别是Q2-87的7倍和6倍。
The broad-spectrum antibiotic 2,4-diacetylphloroglucinol (Phl) is a major determinant in the biological control of a wide range of plant diseases by fluorescent Pseudomonas spp, A protocol was developed to readily isolate and quantify Phl from broth and agar cultures and from the rhizosphere environment of plants, Extraction,vith ethyl acetate at an acidic pH was suitable for both in vitro and in situ sources of Phl, For soil samples, the addition of an initial extraction step with 80% acetone at an acidic pH was highly effective in eliminating polar organic soil components, such as humic and fulvic acids, which can interfere with Phl detection by high-performance liquid chromotography. The efficiency of Phl recovery from soil by a single extraction averaged 54.6%, and a second extraction added another 6.1%. These yields were substantially greater than those achieved by several standard protocols commonly used to extract polar phenolic compounds from soil, For the first time Phl was isolated from the rhizosphere environment in raw soil, Following application of Pseudomonas fluorescens Q2-87 and the Phl-overproducing strain Q2-87(pPHL5122) to the seeds of wheat, 2.1 and 2.4 mu g of Phl/g of root plus rhizosphere soil, respectively, were isolated from wheat grown in a Ritzville silt loam; 0.37 and 1.3 mu g of Phl/g of root plus rhizosphere soil, respectively, were isolated from wheat grown in a Shano silt loam, However, when the amount of Phl was calculated on the basis of cell density, Q2-87(pPHL5122) produced seven and six times more antibiotic than Q2-87 in Ritzville silt loam, and Shano silt loam, respectively.