Long and Medium-Term Research: Factors Affecting the Adaptation Period Preceding Aerobic Degradation of Chlorinated Benzenes

中长期研究：影响氯代苯好氧降解前适应期的因素外国卓越中心长期和中期研究计划，这使得美国科学家和工程师能够在国外被证明是卓越的研究中心进行为期三到十二个月的研究。该项目的奖项提供了联合研究的机会，并提供了使用国外独特或互补的设施、专业知识和实验条件的机会。该奖项将支持亚利桑那大学的Flynn W.Picardal博士与瑞士水资源和水污染控制研究所(EAWAG)的Alexander J.B.Zehnder博士合作进行为期11个月的博士后研究访问。他们的研究项目将研究环境因素对驯化期的影响，驯化期是微生物群生物降解一、二、三氯苯之前的阶段。要检查的因素包括底物的选择、底物浓度、共底物的存在或不存在以及温度。实验将利用包含土壤、水和/或沉积物的微宇宙来检查编码已知退化途径的基因的物种间或菌株间的移动。在这些研究中，氯苯被用作模型化合物，因为氯苯降解的生物化学和遗传学已经被阐明。假单胞菌属菌株P51将被用作供体生物体，以提供能够降解氯苯的基因序列来源。最近分离的这种生物(van der Meer等人，1991)已被证明具有氯苯生物降解基因分组为两个簇。该菌的氯苯加氧酶基因已被证明位于一个转座元件上。通过使用已知的化学和物理诱变剂和其他方法，将刺激种群中的突变和基因重排。DNA杂交和聚合酶链式反应(PCR)技术将被用于研究遗传运动和新遗传物质的获得。这种移动的频率和程度将作为不同的环境因素的函数进行研究。该奖励建议提供了国际旅行费用和11个月的津贴。

Long and Medium-Term Research: Factors Affecting the Adaptation Period Preceding Aerobic Degradation of Chlorinated Benzenes This award is under the Long and Medium-Term Research at Foreign Centers of Excellence Program, which enables U.S. scientists and engineers to conduct three to twelve months of research abroad at research centers of proven excellence. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support an eleven-month postdoctoral research visit by Dr. Flynn W. Picardal of the University of Arizona to work with Dr. Alexander J. B. Zehnder of the Swiss Institute for Water Resources and Water Pollution Control (EAWAG). Their research project will study the effect of environmental factors on the acclimation period which precedes the biodegradation of mono-, di- and trichlorobenzenes by a microbial population. The factors to be examined include choice of substrate, substrate concentration, presence or absence of co-substrate, and temperature. Experiments will utilize microcosms containing soil, water and/or sediments to examine the interspecies or interstrain movement of genes encoding known degradation pathways. Chlorobenzenes are being used as model compounds in these studies because the biochemistry and genetics of chlorobenzene degradation have already been elucidated. Pseudomonas sp. Strain P51 will be used as a donor organism to provide a source of genetic sequences capable of chlorobenzene degradation. This recently isolated organism (van der Meer et al, 1991) has been shown to have chlorobenzene biodegradation genes grouped into two clusters. The chlorobenzene dioxygenase gene for this organism has been shown to be located on a transposable element. Mutations and genetic rearrangements in the population will be stimulated through the use of known chemical and physical mutagens and other methods. DNA hybridization and polymerase chain reaction (PCR) techniques are among those that will be used to study genetic movement and acquisition of new genetic material. The frequency and extent of such movement will be examined as a function of the varied environmental factors. The award recommendation provides funds to cover international travel and a stipend for eleven months.