Project 5: Molecular Insight into Dioxin Degradation by Microbes and Microbial

项目 5：微生物和微生物降解二恶英的分子洞察

基本信息

批准号：
8564240
负责人：
GERBEN J ZYLSTRA
金额：
$ 48.91万
依托单位：
MICHIGAN STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

项目摘要

PROJECT SUMMARY (See instructions): The microbial world is hugely diverse owing to its 3.7 billion years of evolution, which provides for both the opportunity of undiscovered metabolic capacity, including that for pollutant degradation, and the challenge of detecting, recovering, and characterizing this activity. While microbes have been exposed to small amounts of dioxins over millennia due to natural events such as forest fires, it is only in the last century or so that dioxins have become an abundant food source in nature due to anthropogenic activity. This may explain why there are only a few well characterized microbial strains with the ability to mineralize dioxins. We propose to characterize the microbial response to dioxins in pure cultures and microbial communities to understand the limitations on environmental detoxification of this hazardous class of compounds. Our long term goal is to develop microbes for enhanced biodegradation, to identify molecular markers to aid in site assessment, and to develop models for prediction of biodegradation at contaminated sites. Our Specific Aims in the present proposal are: (1) to elucidate the physiology, biochemistry, and genetics of chlorinated dioxins degradation in order to understand and improve the remediation of these highly toxic pollutants, (2) to assess (meta)genome-wide responses and metabolic capabilities by conducting physiogenomic studies of microorganisms and active microbial communities in response to chlorinated dioxins including those from environmentally important geosorbents, and (3) to explore and recover nature's catalytic diversity with the goal of developing a comprehensive profile of microbial community metabolic capabilities for degradation and/or mineralization of chlorinated dioxins and dioxin-like compounds in the environment. We propose to use enrichments to help identify the functionally active populations and hence genes, to use stable isotope probing to recover DNA from the active degrading populations, to use metagenomic and metatranscriptomic libraries and the novel technology of massive parallel RNA bait capture of target DNA and RNA to recover the full genes and operons, to use this information to understand the biochemistry of dioxins degradation, and to use transcriptomic and biochemical analyses of a model dioxin degrading bacterium to understand the total response of the organism to the various pressures involved during the degradation process (i.e. substrate and metabolite toxicity, metabolic fluxes, etc.).

项目摘要（请参阅说明）：由于其37亿年的进化，微生物世界的变化巨大，这既提供了未发现的代谢能力的机会，包括污染物降解的机会，以及检测，恢复和表征这项活动的挑战。由于自然事件（例如森林火灾），在数千年中，微生物在千年中暴露于少量二恶英，但仅在上个世纪左右，二恶英才由于人为活性而成为自然界中丰富的食物来源。这可能解释了为什么只有少数良好的微生物菌株具有矿化二恶英的能力。我们建议表征纯培养物和微生物群落中对二恶英的微生物反应，以了解这种危险类化合物的环境排毒的局限性。我们的长期目标是开发微生物以增强生物降解，鉴定分子标记以帮助进行现场评估，并开发用于预测受污染部位生物降解的模型。我们本提案中我们的具体目的是：（1）阐明氯化二恶英降解的生理，生物化学和遗传学，以了解和改善这些高毒污染物的补救，（2）评估（MetA）基因组基因组的反应和新代谢性的微生物对媒体构成的反应性，并通过对质激素的依赖性进行了渐进式构成能力。二恶英在内的二恶英以及（3）探索和恢复自然的催化多样性的目的是开发微生物群落代谢能力的全面概况，以降解和/或环境中氯化二恶英和二恶英的氯化二恶英和二恶英的化合物。 We propose to use enrichments to help identify the functionally active populations and hence genes, to use stable isotope probing to recover DNA from the active degrading populations, to use metagenomic and metatranscriptomic libraries and the novel technology of massive parallel RNA bait capture of target DNA and RNA to recover the full genes and operons, to use this information to understand the biochemistry of dioxins degradation, and使用降解细菌模型二恶英的转录组和生化分析，以了解生物体对降解过程中所涉及的各种压力的总反应（即底物和代谢物毒性，代谢通量等）。