CAREER: Ecology of Chlororespiring Bacterial Populations and Biochemical Studies of the Dehalogenating Enzyme Systems

我们在自然界中观察到的大多数生物都呼吸氧气，这是包括人类在内的有氧生物存在的先决条件。在许多湖泊和河流沉积物或淹水土壤中，氧气是不可用的，但许多细菌在这样的缺氧(厌氧)环境中茁壮成长。厌氧细菌使用其他化合物来驱动呼吸，而不是氧气，比如硝酸盐、硫酸盐，或者最近的发现所证明的氯化化学物质。使用氯化化合物的呼吸作用破坏了这些氯化化学物质，因此减少了对人类的毒性。该项目将阐明呼吸含氯化合物的细菌种群的分布、丰度、多样性、生理和生态功能。PI将表征所涉及的酶，探索这些细菌中脱氯酶系统的多样性，并探索这些系统的进化。将检查来自不同地理位置(包括南极洲、西伯利亚永久冻土、深层地下、热液喷口和温泉)的样本，并详细研究感兴趣的细菌种群。将使用和改进最先进的基于核酸的工具来检测、监测和量化这些生物体。因为人造氯化化合物(如杀虫剂、溶剂等)是主要的环境污染物，这个项目旨在了解氯呼吸细菌的基本生物学和生态学，可以为探索如何利用这些专门生物来协助污染场地的清理工作提供基础。这是一个集研究和教育活动于一体的职业奖项。本科生和研究生将参与这一研究项目。为了改善少数族裔的参与和教职员工的互动，将启动与波多黎各大学马亚圭兹分校的访问学生研究人员发展(VSRD)计划。此外，高中教师(和他们的学生)将有机会通过参加暑期科学探究项目来体验新技术。

Most living beings we observe in nature breathe oxygen, a prerequisite for the existence of aerobic organisms, including humans. In many lake and river sediments or waterlogged soils oxygen is not available, yet many bacteria thrive in such oxygen-depleted (anaerobic) environments. Instead of oxygen, anaerobic bacteria use other compounds to drive respiration, compounds such as nitrate, sulfate, or, as recent discoveries have demonstrated, chlorinated chemicals. Respiration using chlorinated compounds destroys those chlorinated chemicals, and hence, diminishes toxicity to humans. This project will elucidate distribution, abundance, diversity, physiology, and ecological function of bacterial populations that respire with chlorinated compounds. The PI will characterize the enzymes involved, explore the diversity of dechlorinating enzyme systems in these bacteria, and explore the evolution of these systems. Samples from a variety of geographically distinct locations (including Antarctica, Siberian permafrost, the deep subsurface, hydrothermal vents, and hot springs) will be examined, and bacterial populations of interest will be studied in detail. State-of-the-art nucleic acid-based tools will be used and improved to detect, monitor, and quantify these organisms. Because man-made chlorinated compounds (e.g. pesticides, solvents, etc.) are major environmental pollutants, this project, aimed at understanding the basic biology and ecology of chlororespiring bacteria, can provide a basis for exploring how these specialized organisms can be exploited to assist in clean-up efforts at contaminated sites.This is a CAREER award, integrating research and educational activities. Undergraduate and graduate students will be involved in this research project. To improve minority participation and faculty interaction, a Visiting Student Researcher Development (VSRD) program with the University of Puerto Rico at Mayaguez will be initiated. In addition, high school teachers (and their students) will be given an opportunity to experience new technologies by participating in a summer program of scientific inquiry.