Acinetobacter calcoaceticu WH-B2生物学特性及对桃自毒物质苯甲酸的降解研究
发布时间：2019-03-13 17:07
【摘要】：桃树(Prunus persica)连作障碍是一个世界性的难题,越来越多的研究表明,桃树连作障碍与其根系分泌的自毒物质密切相关。本实验室已从9年生桃树根际土壤中分离出了主要自毒物质苯甲酸降解菌,本研究以其中的乙酸钙不动杆菌(Acinetobacter calcoaceticu)WH-B2为研究对象,对其外观形态、生长和降解特性进行分析,并对该菌株的最适生长和降解条件进行筛选;同时还对自毒物质苯甲酸的降解产物进行了毒性测定,并初步探讨了乙酸钙不动杆菌WH-B2苯甲酸降解基因的定位,以期为乙酸钙不动杆菌WH-B2在缓解连作障碍中的应用以及为后续研究质粒转化及工程菌的研制提供理论依据。试验主要结果如下:1.乙酸钙不动杆菌WH-B2能以苯甲酸作为碳源进行生长繁殖,并且在不同的培养条件下达到最大生长量的时间不同。在液体培养条件下,该菌株自接种后16 h即可达到最大生长量,此时培养基中的苯甲酸含量最低;在土壤培养条件下,菌株在接种后的24 h达到最大生长量,同时土壤中的苯甲酸含量最低。2.乙酸钙不动杆菌WH-B2的生长和降解能力在不同的外界条件下表现出明显的差异。菌株在底物浓度为300 mg/L,温度为30℃,pH=7时表现出最佳生长和降解能力。在苯甲酸存在的前提下,加入适量的葡萄糖和蛋白胨等碳源添加物后,能够促进菌株的生长以及苯甲酸的降解。3.利用化感模式植物莴苣种子的萌发试验对苯甲酸的降解产物进行了毒性测定,结果表明,没有接种菌株且含有苯甲酸的培养基处理的莴苣种子发芽率、发芽势、发芽指数和活力指数均接近于0。降解产物处理组和蒸馏水对照组在各个指标上没有明显差异,但是均显著高于没有接种菌株的处理组。4.通过质粒检测和质粒消除对乙酸钙不动杆菌WH-B2菌株降解基因进行了初步定位,结果表明,该菌株含有质粒,并且该质粒上含有控制降解苯甲酸的基因。
[Abstract]:(Prunus persica) continuous cropping disorder in peach trees is a worldwide problem. More and more studies have shown that the continuous cropping disturbance is closely related to the autotoxic substances secreted by the root system of peach trees. Benzoic acid degrading bacteria were isolated from rhizosphere soil of 9-year-old peach trees. In this study, Acinetobacter calcometrate (Acinetobacter calcoaceticu) WH-B2) was used as the research object, and the appearance and morphology of the bacteria were studied. The growth and degradation characteristics of the strain were analyzed, and the optimum growth and degradation conditions of the strain were screened. At the same time, the toxicity of the degradation products of benzoic acid, an autotoxic substance, was also determined, and the localization of benzoic acid degradation gene of Acinetobacter calcometrate WH-B2 was also discussed. In order to provide a theoretical basis for the application of Acinetobacter calcometrate WH-B2 in the alleviation of continuous cropping obstacles and for the subsequent study of plasmid transformation and the development of engineering bacteria. The main results of the test are as follows: 1. Acinetobacter calcinoacetate WH-B2 could grow and reproduce with benzoic acid as carbon source, and the time of maximum growth was different under different culture conditions. Under the condition of liquid culture, the strain could reach the maximum growth rate 16 hours after inoculation, and the content of benzoic acid in the medium was the lowest. Under the condition of soil culture, the strain reached the maximum growth at 24 h after inoculation, and the content of benzoic acid in soil was the lowest. 2. The growth and degradation ability of Acinetobacter calcinoacetate WH-B2 were significantly different under different external conditions. When the substrate concentration was 300 mg/L, and the temperature was 30 鈩，
本文编号：2439593
[Abstract]:(Prunus persica) continuous cropping disorder in peach trees is a worldwide problem. More and more studies have shown that the continuous cropping disturbance is closely related to the autotoxic substances secreted by the root system of peach trees. Benzoic acid degrading bacteria were isolated from rhizosphere soil of 9-year-old peach trees. In this study, Acinetobacter calcometrate (Acinetobacter calcoaceticu) WH-B2) was used as the research object, and the appearance and morphology of the bacteria were studied. The growth and degradation characteristics of the strain were analyzed, and the optimum growth and degradation conditions of the strain were screened. At the same time, the toxicity of the degradation products of benzoic acid, an autotoxic substance, was also determined, and the localization of benzoic acid degradation gene of Acinetobacter calcometrate WH-B2 was also discussed. In order to provide a theoretical basis for the application of Acinetobacter calcometrate WH-B2 in the alleviation of continuous cropping obstacles and for the subsequent study of plasmid transformation and the development of engineering bacteria. The main results of the test are as follows: 1. Acinetobacter calcinoacetate WH-B2 could grow and reproduce with benzoic acid as carbon source, and the time of maximum growth was different under different culture conditions. Under the condition of liquid culture, the strain could reach the maximum growth rate 16 hours after inoculation, and the content of benzoic acid in the medium was the lowest. Under the condition of soil culture, the strain reached the maximum growth at 24 h after inoculation, and the content of benzoic acid in soil was the lowest. 2. The growth and degradation ability of Acinetobacter calcinoacetate WH-B2 were significantly different under different external conditions. When the substrate concentration was 300 mg/L, and the temperature was 30 鈩，
本文编号：2439593
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