Novel Approaches to Studying the Situ Bioremediation of Complex Mixtures

美国和巴尔的摩/切萨皮克湾地区的绝大多数超级基金地点都含有以下物质的混合物 污染地下蓄水层的有机和无机化合物。它们的环境命运 污染物，并最终人类暴露于他们，主要是由他们的相互作用， 微生物是什么？个人或作为一个社区？推动原位生物修复的进程。 尽管单一污染物/微生物相互作用可以在实验室中容易地确定，但没有令人满意的结果。 目前已有各种工具可用于预测混合物在环境中的归宿。我们的长远目标是改善 通过使用原位微宇宙在含有复杂化学混合物的场所进行生物修复的成功率 阵列（ISMA）技术。ISMA是一个可现场部署的小型实验室，由一个大型 平行排列的许多小微观世界。在部署、孵化和从 地下水井，ISMA可以分析，以揭示混合物成分对地下水渗透率的影响。 污染物降解与微生物群落结构和功能。我们假设 ISMA可以帮助生物修复策略的设计，因为：（1）个体ISMA微观世界可以 用多种测试物质进行修正，以阐明混合物组分对微生物的影响;（2） 微生物对所呈现化合物的响应表现为生物量的变化， 群落结构和功能;（3）这些变化可以通过生物化学， 基因和蛋白质组学策略。根据上述意见，该项目的具体目标是： 1.确定ISMA技术的再现性和区分能力。我们将探讨如何 不同浓度的诱导剂和合成地下水中的共污染物调节表达， 通过大量的重复实验，对鞘氨醇单胞菌RW 1菌株的二恶英双加氧酶（DD酶 与半自动化高通量蛋白质组质谱联用。 2.在受控实验室条件下演示ISMA如何揭示加和、协同和 混合组分对微生物群落的拮抗作用。我们将使用定义的混合物， 化学品（例如，二恶英、多氯联苯、多环芳烃、甲苯甲醛、镉、铬、钴、铅、汞、锌、镍）和细菌（5种 生物修复剂）以研究各种排列中的这些效果。 3.评估ISMA技术在模拟现场条件下的实用性。我们将进行ISMA实验室 实验使用非无菌地下水，沉积物和天然微生物群落。 4.在马里兰州超级基金站点部署ISMA设备。我们将评估新技术的实用性， 现场示范研究，通过原位检测菌株RW 1的存活率和DD酶表达， 阐明了这种引入的细菌对该地点的土著微生物群落的影响。

The vast majority of Superfund sites in the U.S and the Baltimore/Chesapeake Bay area contain mixtures of organic and inorganic compounds that contaminate underlying aquifers. The environmental fate of these contaminants, and ultimately human exposure to them, is governed primarily by their interactions with microorganisms, which?individually or as a community?drive the process of in situ bioremediation. Whereas single pollutant/microorganism interactions can be determined easily in the lab, no satisfactory tools exist for predicting the fate of mixtures in the environment. Our long-term goal is to improve the success rate of bioremediation at sites containing complex chemical mixtures by using in situ microcosm array (ISMA) technology. The ISMA is a field-deployable, miniaturized laboratory consisting of a large number of small microcosms arranged in parallel. Upon deployment, incubation, and retrieval from a groundwater well, the ISMA can be analyzed to reveal the impact of mixture components on the rates of Dollutant degradation and on the structure and function of microbial communities. We hypothesize that the ISMA can aid in the design of bioremediation strategies because: (1) individual ISMA microcosms can be amended with multiple test substances to elucidate the effect of mixture components on microorganisms; (2) the response of microorganisms to presented compounds manifests itself as changes in biomass, community structure and function; and (3) these changes can be detected conveniently by biochemical, genetic and proteomic strategies. Based on the above observations, the specific aims of the project are to: 1. Determine the reproducibility and discriminatory power of the ISMA technology. We will explore how varying concentrations of inducers and co-contaminants in synthetic groundwater modulate the expression of the dioxin dioxygenase (DDase) of Sphingomonas wittichii Strain RW1, by using a large number of replicates in conjunction with semi-automated, high-throughput proteomic mass spectrometry. 2. Demonstrate in controlled laboratory conditions how the ISMA can reveal additive, synergistic, and antagonistic effects of mixture components on microbial communities. We will use defined mixtures of chemicals (e.g., dioxins, PCBs, PAHs, tolualdeyhyde, Cd, Cr, Co, Pb, Hg, Zn, Ni) and bacteria (five bioremediation agents) to study these effects in various permutations. 3. Evaluate the utility of the ISMA technology in simulated field conditions. We will conduct ISMA laboratory experiments using nonsterile groundwater, sediment, and natural microbial communities. 4. Deploy the ISMA device at a Maryland Superfund site. We will assess the utility of the new technology in a field demonstration study by examining survival of and DDase expression by Strain RW1 in situ, and by elucidating the impact of this introduced bacterium on the indigenous microbial community at the site.