Biogeochemical Controls over Corrinoid Bioavailability to Organohalide-Respiring

描述（由申请人提供）：接触被有毒化学物质污染的水威胁人体健康。根除美国约12.6万个危险废物场所将需要1000多亿美元。这项工作结合了净化污染、恢复环境和迅速保护人类健康所迫切需要的创新和经济高效的技术。四氯乙烯（PCE）和三氯乙烯（TCE）等氯化溶剂及其转化产物二氯乙烯（dce）和氯乙烯（VC）是主要的风险驱动因素，与免疫系统受损、致癌、肾和肝损伤以及帕金森病有关。对微生物学的科学理解涉及到还原脱氯到无毒的乙烯已经激发了清理工作在氯化乙烯场所。虽然有希望，但当低效的DCE和VC还原脱氯导致DCE/VC停滞时，解毒和站点关闭通常无法实现。麦卡蒂脱盐球菌（Dehalococcoides mccartyi, Dhc）菌株是参与dce和VC还原脱氯生成环境友好的乙烯的关键细菌。对Dhc生态生理和营养需求的了解有望提高DCE和VC的脱氯率，克服DCE/VC的停滞，并导致更有效的生物修复，以减少人类与这些危险化学品的接触。结合以培养为基础的方法，高通量测序，生物信息学分析和最先进的分析方法的详细研究将揭示生物地球化学条件，在这些条件下，Dhc还原脱氯活性不受足够的类椰碱辅助因子供应的限制。一个创新的,

DESCRIPTION (provided by applicant): Exposure to water tainted with toxic chemicals threatens human health. In excess of $100 billion will be required to eradicate the ~126,000 hazardous waste sites in the U.S. This effort incorporates innovative and cost-efficient technologies that are urgently needed for decontamination, environmental restoration and prompt protection of human health. Chlorinated solvents like tetrachloroethene (PCE) and trichloroethene (TCE), and their transformation products, dichloroethenes (DCEs) and vinyl chloride (VC), are major risk drivers and are linked to compromised immune systems, carcinogenesis, kidney and liver damage, and Parkinson's disease. Scientific understanding of the microbiology involved in reductive dechlorination to non-toxic ethene has invigorated cleanup efforts at chlorinated ethene sites. Although promising, detoxification and site closures are often not achieved when inefficient DCE and VC reductive dechlorination leads to DCE/VC stalls. Dehalococcoides mccartyi (Dhc) strains are keystone bacteria involved in the reductive dechlorination of DCEs and VC to environmentally benign ethene. Knowledge of Dhc ecophysiology and nutritional requirements promises to increase DCE and VC dechlorination rates, overcome DCE/VC stalls, and lead to more efficient bioremediation to reduce human contact with these dangerous chemicals. Detailed studies combining cultivation-based approaches, high-throughput sequencing, bioinformatics analyses, and state-of-the art analytical procedures will reveal the biogeochemical conditions, under which Dhc reductive dechloirnation activity is/is not constrained by adequate corrinoid cofactor supply. An innovative, high-throughput quantitative PCR tool (i.e., the B12-qChip) will be designed, validated and made available to the community to recognize when corrinoid bioavailability limits Dhc reductive dechlorination activity. Application of the new tool and knowledge will improve contaminated site management by enabling site specific treatment to achieve efficient detoxification, effectively protect human exposure to toxic and carcinogenic chemicals, reduce remediation times and costs, while mitigating negative secondary environmental impacts of bioremediation treatment (e.g., lower greenhouse gas emissions, stable pH avoids toxic metal release).