FOR 1530: Anaerobic Biological Dehalogenation: Organisms, Biochemistry and (Eco-)Physiology

在许多地点都能检测到卤化烃。它们可能是自然的，也可能是人为的。特别是那些由人类活动释放到环境中的卤代化合物往往对生态有害、有毒和/或致癌；此外，挥发性卤化化合物破坏了我们星球的臭氧层。通常卤化化合物，如四氯乙烯，在受污染的地点具有广泛的顽固性，因为它们分别以相当低的速率降解或去卤化。在这些地点，高氯化化合物（例如PCE）的生物脱氯是由严格的厌氧细菌进行的，这些细菌能够在缺氧的情况下与卤代烃一起呼吸（有机卤化物呼吸）。在这个呼吸过程中，卤化化合物被还原去卤。这个过程与ATP的合成相结合，意味着能量的节约。研究股将集中研究有机卤化物呼吸作用。在本研究的过程中，将对这种新型厌氧呼吸的所有重要方面进行研究。这些方面包括生理生化催化机制、能量守恒机制、呼吸链的结构和拓扑以及相关成分的调控。这些研究的先决条件是有机盐呼吸细菌基因组的知识。一些基因组序列已经已知并发表，其他的将作为研究单位的一部分在研究项目中揭示。在这些序列的基础上，可以在适当的实验条件下确定有机卤化物呼吸链的组分，并在以后进行更详细的表征。计划中的研究一方面将有助于了解有机卤化物呼吸作用及其在全球卤素循环中的作用，另一方面将有助于将这一过程应用于被卤化化合物污染的场所的生物修复。

Halogenated hydrocarbons can be detected at many sites. They may be of natural or anthropogenic origin. Especially those halogenated compounds released into the environment by human activities are often ecologically harmful, toxic, and/or carcinogenic; moreover, volatile halogenated compounds destroy the ozone layer of our planet. Frequently halogenated compounds such as tetrachloroethene (PCE) are widely recalcitrant at contaminated sites, since they are degraded or dehalogenated, respectively, only at rather low rates. The biological dechlorination of highly chlorinated compounds, e.g. PCE, at such sites is performed by strictly anaerobic bacteria that are able to respire with halogenated hydrocarbons (organohalide respiration) in the absence of oxygen. In the course of this respiration, the halogenated compounds are reductively dehalogenated. This process is coupled to the synthesis of ATP, meaning energy conservation. The Research Unit will focus on the organohalide respiration. In the course of this research, all significant aspects of this novel type of anaerobic respiration will be investigated. These aspects comprise the physiology and biochemical catalytic mechanisms as well as the mechanisms of energy conservation, the structure and topology of the respiratory chain and the regulation of the components involved. A prerequisite for these studies is the knowledge of the genomes of organohalide-respiring bacteria. A few genome sequences are already known and published, others will be revealed in the research projects as parts of the Research Unit. On the basis of these sequences, the components of the organohalide respiratory chain may be identified under appropriate experimental conditions and may later be characterised in more detail. The planned studies will contribute, on the one hand, to the understanding of the organohalide respiration and its role in the global halogen cycle and, on the other hand, to the application of this process for the bioremediation of sites contaminated with halogenated compounds.