竹炭固定化紫外诱变假单胞菌处理间甲酚废水的研究     

周珊  虞方伯  郭明  单胜道  邸玉翠  徐少娟  李松华  郑圣丰 《林业科学》2011,47(9)

用紫外光对假单胞菌株进行诱变,以竹炭为载体,将紫外诱变假单胞菌固定在竹炭上,用竹炭固定化紫外诱变假单胞菌处理间甲酚水样。考察竹炭固定化紫外诱变假单胞菌投加量和水样pH值对间甲酚去除的影响以及进水浓度随反应时间的变化关系,研究竹炭固定化紫外诱变假单胞菌去除间甲酚的反应动力学。结果表明:相对于原菌株,菌株经紫外诱变后,生长周期缩短了6h。经紫外照射120s的假单胞菌可以在竹炭表面及内部孔隙形成明显菌胶团,诱变菌在竹炭上所成的生物量明显较未经诱变菌增加。竹炭固定化紫外诱变假单胞菌能有效地去除水样中间甲酚。竹炭固定化紫外诱变假单胞菌投加量和水样pH值影响到间甲酚的去除效果,pH值在4～6时,间甲酚的去除效果较好。20g竹炭固定化紫外诱变假单胞菌处理100mL初始浓度50,100,120,150,180mg·L-1间甲酚模拟水样42h,去除率依次为90.9%,76.4%,72.9%,64.6%和49.7%。竹炭固定化紫外诱变假单胞菌对间甲酚的去除能较好地符合零级反应方程。  相似文献   

Pine wilt disease: a short review of worldwide research   总被引：1，自引：0，他引：1  

Alexander Yu. RYSS  Oleg A. KULINICH  Jack R. SUTHERLAND 《中国林学(英文版)》2011,13(2):132-138

This article summarizes the results of the research papers presented at the International Symposium on pine wilt disease (IUFRO Working Party Meeting 4.04.03) held in July 2009, at Nanjing, China. The general topics covered were on pine wilt disease (PWD), its causal organism, the pinewood nematode (PWN) Bursaphelenchus xylophilus, plus other PWN-associated microorganisms that play a significant role in PWD such as bacteria (e.g. Pseudomonas fluorescens). Most of the papers that are reviewed are based on work on PWD-PWN in East Asia and Russia. Specific topics covered include: 1) the fundamental conceptions of PWD development, 2) pathogenicity, 3) host-parasite relationships including the histopathology of diseased conifers and the role of toxins from bacteria-nematode ecto-symbionts, 4) PWN life cycle and transmission, 5) B. xylophilus dissemination models, 6) associations (with other nematodes), 7) diagnostics, 8) quarantine and control of the PWN and 9) biocontrol of the PWN.  相似文献   

Quantification of the biocontrol agent Pseudomonas fluorescens Pf153 in soil using a quantitative competitive PCR assay unaffected by variability in cell lysis- and DNA-extraction efficiency     

Davide Gobbin  Fabio Rezzonico  Cesare Gessler 《Soil biology & biochemistry》2007,39(7):1609-1619

Although often neglected, variability in cell lysis efficiency and DNA extraction yield represents the major hurdles of any polymerase chain reaction (PCR)-based quantification protocol in soil and other natural environments. In this study we developed a technique that minimizes the effects of these constraints, providing at the same time a reliable internal control to distinguish between PCR-inhibition and negative results. We used Pseudomonas fluorescens Pf153, a root-colonizing bacterium that shows biocontrol activity against tobacco and cucumber black root rot, as the target organism for PCR quantification. Prior to DNA extraction, the genetically engineered, cognate reference strain P. fluorescens CHA0/c2 was inoculated in a reference soil. CHA0/c2 in the reference soil and Pf153 in the soil sample were lysed in parallel and afterward the lysates were mixed in known proportions. CHA0/c2 carries the plasmid pME6031-cmp2 that contains an allelic variant (competitor) of the Pf153 specific sequence Pf153_2. In a quantitative competitive PCR (QC-PCR) assay the competitor allows the quantification of the target strain down to 0.66 Pf153 CFU/mg soil. Processing the reference strain in the same way as Pf153 enables the exact quantification of the target strain in biocontrol assays performed in natural soil, overcoming differences in DNA extraction efficiency and PCR amplification from different soil environments. This technique is easily adaptable to other Pseudomonas strains simply by replacing the competitor used here with one derived from a SCAR-marker which is specific for the strain of choice.  相似文献   

Relative importance of motility and antibiosis in the rhizoplane competence of a biocontrol agent Pseudomonas fluorescens MelRC2Rif     

K. Toyota  K. Ikeda 《Biology and Fertility of Soils》1997,25(4):416-420

Mutants defective in motility or antibiotics production were obtained by Tn5 mutagenesis of a biocontrol agent Pseudomonas fluorescens MelRC2Rif (wt). Tomato or melon seeds were co-inoculated with a Tn5 mutant and wt in a 1:1 ratio and then grown in soil for 10 days. There was no change in ratios of Tn5 mutants defective in antibiosis to wt in the process of rhizoplane colonization, suggesting little contribution of in vitro antibiosis to the rhizoplane competence of P. fluorescens MelRC2Rif. Similar results were also obtained when seeds treated with bacteria were planted in soil artificially infested with fungal pathogens. In contrast, ratios of Tn5 mutants defective in motility to wt significantly decreased, suggesting the contribution of motility to the rhizoplane competence of this bacterium. When a non-motile Tn5 mutant and wt were co-inoculated into soil at a matric potential of pF 2.3 (–20 kPa) and plants were then grown, there was no change in the ratio in rhizoplane colonization, suggesting that motility might have a role in the movement along roots but an insignificant role in the movement from bulk soil towards roots. When they were co-inoculated into 0.2% water agar (WA) instead of soil, a remarkable decline in ratios was detected. Thus it was soil structure that hindered the efficiency of motility. Time course enumeration of rhizoplane colonization of tomatoes grown in WA revealed that motility was an important means of movement towards and/or along roots rather than the multiplication on roots. Received: 8 July 1996  相似文献   

桉树焦枯病和青枯病的分离鉴定与防治方法     

裴文军  卢万鸿 《桉树科技》2011,(1):57-60

简要概述了危害我国华南地区桉树产业发展的主要病害——桉树焦枯病和青枯病,介绍了两种病害的部分研究方法,分析了两种病害的防治方法及其研究方向,以期为相关研究提供借鉴。  相似文献   

烟草野火病菌初侵染源的研究     

刘雅婷  张世珖  李永忠 《湖南农业大学学报(自然科学版)》2003,29(1):43-44

为探明烟草野火病菌的初侵染源，应用SPA－ELISA，间接－ELISA反应试剂盒对从田间及温室中采集的土壤、烟株根围、田间杂草、种子等进行了检测，明确云南烟草野火病的初侵染源主要为种子和根部残体。  相似文献   

万寿菊细菌性叶斑病的发生与病原菌鉴定   总被引：5，自引：1，他引：5  

高洁  白庆荣  董然  冯玉才  张佳环  刘学敏 《吉林农业大学学报》2002,24(2):94-96,107

首次报道了万寿菊细菌性叶斑病在我国的发生，从吉林省敦化市不同地点、不同部位发病的万寿菊上分离出有致病性的4个菌株，通过对其形态学、培养性状、生理生化性状及生态学的测定，并根据其引起病害的症状特点，将其确定为丁香假单胞菌万寿菊致病变种（Pseudomonas syringae pv. tagetis (Hellmers 1955) Young et al 1978）。  相似文献   

番茄新品种特宝1号苗期对青枯病的抗性测定     

黄宇红 《广西农业科学》2005,36(5):448-449

对从荷兰引进的番茄新品种特宝1号进行番茄青枯病（Ralstonia solanacearum）抗性测定试验,结果表明,该品种表现出较好的抗性.苗期人工接种后,30d才出现症状,比抗病品种抗青1号的发病时间推迟15d,发病率低且病害发展缓慢,校正发病率差异达到极显著水平.该品种还具有早熟、生长势强、不易早衰、丰产性好和特别耐贮运等特点.  相似文献   

铜绿假单胞菌脂肪酶Lipase基因的原核表达     

张煜星  武寒雪  祝建波  刘焕  周鹏 《安徽农业科学》2008,36(35)

[目的]对铜绿假单胞菌脂肪酶Lipase基因进行原核表达。[方法]利用PCR方法从铜绿假单胞菌基因组DNA中扩增得到脂肪酶基因,测定其核苷酸序列,利用基因重组技术构建脂肪酶基因的原核表达载体,加IPTG至终浓度为1.0 mmol/L诱导蛋白表达4 h,并进行SDS-PAGE电泳。[结果]从铜绿假单胞菌中克隆的脂肪酶基因成熟肽的序列,与NCBI上所递交的铜绿假单胞菌脂肪酶序列同源性很高,达99.36%。成功构建了脂肪酶基因的原核表达载体pET32a-Lip,进一步SDS-PAGE电泳结果显示目的基因得到高效表达。[结论]克隆的铜绿假单胞菌脂肪酶带有自身的信号肽,也可以在大肠杆菌中正常表达,可以用于进一步的研究。  相似文献   

消毒剂对烟草漂浮育苗材料表面青枯雷尔氏菌的杀灭作用^*     

刘勇  王敏  李梅云  李永平 《云南农业大学学报(自然科学版)》2008,23(4):483-487

 为了指导烟草漂浮育苗消毒剂使用,通过载体表面菌落杀灭试验,测定了10种消毒剂对聚苯乙烯泡沫苗盘、聚氯乙烯塑料膜和不锈钢刀片表面的青枯雷尔氏菌（Ralstonia solanacoarum,简称青枯菌）的杀灭效果。结果表明,除98％磷酸三钠300 mg/L和24％混脂酸铜80 mg/L对青枯菌几乎没有杀灭作用外,其余消毒剂具有较好的杀灭效果。在聚苯乙烯泡沫苗盘、聚氯乙烯塑料池膜和不锈钢刀片表面,8种消毒剂的90％致死剂量（EC₉₀）差异大,30％有效氯漂白粉为96.4～145.7 mg/L,7％有效氯次氯酸钠为53.7～215.3 mg/L,美国消毒剂为26.2～83.5 mg/L,98％硫酸铜·5H₂O 为93.8～114.0 mg/L; 98％高锰酸钾为14.8～163.0 mg/L;40％育宝为247.7～404.6 mg/L;10％二氧化氯（维绿）为185.7～472.9 mg/L;0.6％菌毒净为101.6～441.0 mg/L。消毒剂的使用剂量需要根据表面材料种类选择。  相似文献