Starter Grant: Molecular Detection of Diverse Arsenic Transforming Prokaryotes and Their Activities in Estuarine Sediments.

砷被美国环境保护署列为致癌物质，该机构将饮用水中允许的最高砷含量从50 ppb降至10 ppb，以防止大量癌症死亡和其他疾病。环境中砷污染物的水平与砷转化过程中的微生物活动密切相关。不同的微生物菌株进行了调查，了解砷生物转化的生理和遗传。然而，在原位微生物活动的砷转化在环境中还没有得到很好的记录和未培养的砷变压器的多样性还没有得到充分阐明。分子工具已经开发出来，以检测砷变压器从环境样品和确定存在的各种未培养的砷转化细菌在切萨皮克湾沉积物。 本研究将在前人研究的基础上，通过量化编码砷转化的功能基因，确定砷转化的原位微生物活性。此外，未培养的土著砷转化微生物在沉积物社区将使用环境基因组的方法来检查其基因组多样性。因此，这项研究将提供更好地了解一般的微生物多样性和特定的相互作用有关的砷转化在自然sediment.The更广泛的意义，这项研究包括严格的洞察到沉积物中的砷的动态。 这项研究的结果也是重要的，以评估砷在地下水系统中的命运和运输。 这项研究还将支持研究生和本科生（高级荣誉）的教育和培训。

Arsenic is classified as a carcinogen by the U.S. Environmental Protection Agency, which lowered the allowable maximum arsenic levels in drinking water from 50 ppb to 10 ppb to prevent a significant number of cancer death and other illnesses. The levels of arsenic contaminants found in environments are strongly related to microbial activities involved in arsenic transformation. Diverse microbial isolates have been investigated to understand the physiology and genetics of arsenic biotransformation. However, in situ microbial activities of arsenic transformation in the environment have not been well documented and the diversity of uncultivated arsenic transformers has not been fully elucidated. Molecular tools have been developed to detect arsenic transformers from environmental samples and determine the presence of diverse uncultured arsenic-transforming bacteria in Chesapeake Bay sediments. Building upon previous studies, this project will determine in situ microbial activities of arsenic transformation by quantifying the functional genes encoding arsenic transformation. In addition, uncultured indigenous arsenic-transforming microorganisms in sediment communities will be accessed using environmental genomic approaches to examine their genomic diversity. Thus, this proposed research will provide better understanding of general microbial diversity and specific interactions related to arsenic transformation in natural sediments.The broader significance of this research consists of the rigorous insights gained into the dynamics of arsenic in sediments. Results of this research are also of importance to assess the fate and transport of arsenic in groundwater systems. This research will also support the education and training of graduate and undergraduate (senior honors) students.