Distribution of contaminant degraders and redox guilds and expression of degradation genes in stationary and non-stationary contaminant plumes

污染物降解剂和氧化还原基团的分布以及固定和非固定污染物羽流中降解基因的表达

• 批准号: 34773108
• 负责人: Professor Dr. Tillmann Lüders
• 金额: --
• 依托单位: Lehrstuhl für Ökologische Mikrobiologie (ÖMIK)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/34773108?language=en
• 关键词: Distribution; contaminant; degraders; redox; guilds

The aim of TP4B in this Research Unit is to understand how redox oscillations and hydraulic shifts influence the spatial distribution and activity of contaminant degraders and anaerobic microbial communities in the field. It is a central hypothesis of this Research Unit that increased mixing in contaminant plumes under non-stationary conditions can be expected to enhance net biodegradation activities. On the other hand, we hypothesize that well established biological degradation capacities (i.e. highly specialised degrader populations) are an essential prerequisite for effective biodegradation in highly reactive zones. Biodegradation can be hypothesized to decrease or even collapse transiently under redox fluctuations caused by hydraulic shifts, if sessile degrader populations suddenly face opposing biogeochemical conditions, and have to re-establish in different sediment strata. In the 2nd phase of funding of the FOR252, we have provided primary evidence that the qualitative and quantitative distribution patterns of important contaminant-degrading microbial populations are subject to unexpected temporal dynamics in the field. An observed “collapse” of the established degrader population was connected to pronounced temporal oscillations of the contaminant plume. These are novel findings that will help to establish a more detailed understanding of the factors that affect and control contaminant degrading microbial populations in the field. In the last 1.5 years of this Research Unit (12 months of funding we hereby apply for), we aim to further elaborate and more profoundly establish these concepts by continued time-resolved samplings in the field, addressing also short-time dynamics. Furthermore, an established luminescent bioreporter strain will be employed in 2D aquifer mesocosms to follow and model the development of a specific degrader population and activities over the establishment of a contaminant plume, and also under non-stationary conditions. Thus, simulations of the distribution of microbial degradation activities and their adaptation to increased mixing for the tanks will actually become testable with temporally and spatially resolved non-invasive data.

本研究单元TP4B的目的是了解氧化还原振荡和水力变化如何影响该领域污染物降解剂和厌氧微生物群落的空间分布和活动。本研究单位的一个中心假设是，在非固定条件下增加污染物羽流的混合可以预期增强净生物降解活动。另一方面，我们假设建立良好的生物降解能力（即高度专业化的降解生物种群）是在高反应区进行有效生物降解的必要先决条件。如果固定式降解生物种群突然面临相反的生物地球化学条件，必须在不同的沉积物地层中重新建立，那么在水力位移引起的氧化还原波动下，生物降解可以被假设为减少甚至暂时崩溃。在FOR252资助的第二阶段，我们提供了主要证据，证明重要污染物降解微生物种群的定性和定量分布模式受到该领域意想不到的时间动态的影响。观察到的已建立的降解菌种群的“崩溃”与污染物羽流明显的时间振荡有关。这些新发现将有助于更详细地了解影响和控制该领域污染物降解微生物种群的因素。在这个研究单位的最后一年半（我们在此申请的12个月的资金），我们的目标是通过在该领域继续进行时间分辨采样，进一步阐述和更深刻地建立这些概念，同时解决短期动态问题。此外，一个已建立的发光生物报告菌株将在二维含水层中生态系统中使用，以跟踪和模拟特定降解菌群的发展和污染物羽流的建立以及非平稳条件下的活动。因此，模拟微生物降解活动的分布及其对增加混合的适应，实际上可以用时间和空间分辨的非侵入性数据进行测试。