Biogeochemical Controls over Corrinoid Bioavailability to Organohalide-Respiring

描述（由申请人提供）：暴露于有毒化学品污染的水威胁人类健康。需要超过1000亿美元来消除美国约126，000个危险废物场地，这一努力采用了去污、环境恢复和迅速保护人类健康所迫切需要的创新和具有成本效益的技术。氯化溶剂，如四氯乙烯（PCE）和三氯乙烯（TCE），以及它们的转化产物，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，肾脏和肝脏损伤以及帕金森病有关。对还原脱氯生成无毒乙烯过程中所涉及的微生物学的科学认识，已大大加强了氯化乙烯场所的清理工作。尽管前景看好，但当二氯乙烷和氯乙烯还原脱氯效率低下导致二氯乙烷/氯乙烯停滞时，解毒和场址关闭往往无法实现。Mccartyi脱卤球菌（Dehalococcoides mccartyi，Dhc）是参与DCE和VC还原脱氯生成环境友好型乙烯的关键细菌。DHC的生态生理学和营养需求的知识有望提高DCE和VC脱氯率，克服DCE/VC失速，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。结合基于培养的方法、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DHc还原脱氯活性不受足够的类咕啉辅因子供应限制的生物化学条件。一个创新的， 高通量定量PCR工具（即，B12-qChip）将被设计、验证并提供给社区，以识别何时类可丽素生物利用度限制了Dhc还原脱氯活性。新工具和新知识的应用将改善受污染场地的管理，使场地特定处理能够实现有效解毒，有效保护人类接触有毒和致癌化学品，减少补救时间和成本，同时减轻生物补救处理的负面次级环境影响（例如，更低的温室气体排放，稳定的pH值避免有毒金属释放）。

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).