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网站都包含 污染地下含水层的有机和无机化合物。它们在环境上的命运 污染物，以及最终人类对它们的暴露，主要由它们与 微生物，无论是单独的还是作为一个群体，推动着就地生物修复的进程。 然而，单一污染物/微生物的相互作用在实验室中很容易确定，但并不令人满意 有一些工具可以预测混合物在环境中的命运。我们的长期目标是改善 利用原位微宇宙研究复杂化学混合物场所生物修复的成功率 阵列(ISMA)技术。ISMA是一个可现场部署的微型实验室，由一个大型 平行排列的小微观世界的数量。在部署、孵化和从 对于地下水井，可以通过分析ISMA来揭示混合物组分对水平率的影响。 对污染物降解和微生物群落结构和功能的影响。我们假设 ISMA可以帮助设计生物修复策略，因为：(1)单个ISMA微观世界可以 修正多种测试物质，阐明混合物成分对微生物的影响；(2) 微生物对现有化合物的反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化方法方便地检测到， 遗传和蛋白质组学策略。基于上述观察，该项目的具体目标是： 1.确定ISMA技术的重复性和鉴别力。我们将探讨如何 合成地下水中不同浓度的诱导剂和共污染物调节 维氏鞘氨醇单胞菌RW1菌株的二恶英双加氧酶(DDase) 与半自动、高通量蛋白质组质谱结合使用。 2.在受控实验室条件下演示ISMA如何显示添加剂、协同作用和 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(如二恶英、多氯联苯、多环芳烃、甲苯醛、镉、铬、钴、铅、汞、锌、镍)和细菌(五种 生物修复试剂)来研究这些在各种排列中的影响。 3.在模拟野外条件下评价ISMA技术的实用性。我们将进行ISMA实验室 使用非无菌地下水、沉积物和自然微生物群落的实验。 4.在马里兰州超级基金网站部署ISMA设备。我们将评估这项新技术的效用 RW1菌株的存活和DDase表达的现场示范研究 阐明这种引入的细菌对工地本地微生物群落的影响。

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.