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

我们在自然界观察到的大多数生物都呼吸氧气，这是有氧生物（包括人类）存在的先决条件。在许多湖泊和河流沉积物或浸水土壤中，氧气是不可用的，然而许多细菌在这种缺氧（厌氧）环境中茁壮成长。厌氧细菌利用其他化合物代替氧气来驱动呼吸作用，这些化合物包括硝酸盐、硫酸盐，或者最近发现的氯化化学物质。使用氯化化合物的呼吸作用会破坏这些氯化化学物质，从而降低对人体的毒性。本项目将阐明与含氯化合物呼吸的细菌种群的分布、丰度、多样性、生理和生态功能。PI将描述所涉及的酶，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。将对来自不同地理位置（包括南极洲、西伯利亚永久冻土、地下深处、热液喷口和温泉）的样品进行检查，并对感兴趣的细菌种群进行详细研究。将使用并改进最先进的核酸工具来检测、监测和量化这些生物体。由于人造氯化化合物（如杀虫剂、溶剂等）是主要的环境污染物，本项目旨在了解吸氯细菌的基本生物学和生态学，为探索如何利用这些特殊的生物来协助污染场地的清理工作提供基础。这是一个职业奖，集研究和教育活动于一体。本科生和研究生将参与本研究项目。为了提高少数民族的参与和教师的互动，将与波多黎各大学马亚圭斯分校启动一个访问学生研究人员发展（VSRD）项目。此外，高中教师（及其学生）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.