MICROBIAL DEGRADATION OF PAH MIXTURES & THEIR INTERMEDIATES

描述（摘自应用程序） 许多环境中都含有多环芳烃（PAHs）和N-杂环芳烃。 芳香族化合物（NHAs）作为复杂的混合物。3000名前 含多环芳烃和氨杂环芳烃的煤气化厂的网站构成主要 健康危害在美国的总体目标是提高 多环芳烃混合物的生物降解和矿化， 含金属和多环芳烃污染土壤中的多环芳烃及其代谢产物。 该提案针对的是具有致癌性的4环和5环多环芳烃， NHAs和混合物在这些土壤中。重点是表征生物化学 和遗传基础的多环芳烃降解途径，并确定 多环芳烃和金属的复杂混合物对这些降解途径的影响。 因此，具体的目标是：1）确定生物降解模式 多环芳烃混合物相对于单个多环芳烃的影响以及金属对 2）测定4、5环多环芳烃的降解能力 降解剂（和3-5环NHA降解剂）进行限制步骤， 土壤微生物代谢; 3）识别和表征遗传 高分子量PAH（和NHA）降解的基础。这项研究将 包括确定代谢和矿化率，代谢 中间体、反应序列和反应产物的积累 HPLC/MS/荧光。藻类最初代谢混合物的能力， 低分子量降解剂和土壤微生物降解 将通过HPLC/MS/荧光法测定部分代谢的PAH混合物。 将鉴定高分子量降解剂的PAH降解基因 以及与其他化学品的功能性和序列相关性， 已知的基因将被确定。最后，PAH的发生和分布 利用PCR引物对土壤中的降解基因进行检测 基于序列信息。了解了微生物 在碳氢化合物降解过程中，将制定战略， 去除污染土壤中的多环芳烃、氨杂环芳烃及其中间体。

DESCRIPTION (Taken from application) Many environments contain polycyclic aromatic hydrocarbons (PAHs) and N-heterocyclic aromatics (NHAs) as complex mixtures. Specifically, 3000 former sites of coal gasification plants containing PAHs and NHAs constitute major health hazards in the U.S. The overall objective is to enhance the biodegradation and mineralization of mixtures of PAHs for the elimination of PAHs and their metabolites from polluted soils containing metals and PAHs. This proposal targets the recalcitrant, carcinogenic 4 and 5 ring PAHs and NHAs and mixtures in these soils. The focus is to characterize the biochemical and genetic basis of PAH degradation pathways in bacteria and determine the effects of complex mixtures of PAHs and metals on these degradation pathways. Therefore, the specific aims are to: 1) determine the biodegradation pattern of PAH mixtures relative to individual PAHs and the impact of metals on bacterial biodegradation; 2) determine the ability of 4 and 5 ring PAH degraders(and 3-5 ring NHA degraders) to perform the limiting step in metabolism for soil microorganisms; 3) identify and characterize the genetic basis for high molecular weight PAH (and NHA) degradation. This research will involve determining the metabolism and mineralization rates, metabolic intermediates, reaction sequences and accumulation of reaction products by HPLC/MS/fluorescence. The ability of algae to initially metabolize mixtures, and low molecular weight degraders and soil microorganisms to degrade partially metabolized PAH mixtures will be determined by HPLC/MS/fluorescence. PAH degradative genes for high molecular weight degraders will be identified and characterized and the functionality and sequence relatedness to other known genes will be determined. Lastly, the occurrence and distribution of PAH degradative genes in soil populations will be determined using PCR primers based on sequence information. With an understanding of the microbial hydrocarbon degradation process, strategies will be developed to enhance the removal of PAHs, NHAs and their intermediates from contaminated soils.