MICROBIAL DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBON MIXTURES

多环芳烃混合物的微生物降解

• 批准号: 6271076
• 负责人: DAVID WARSHAWSKY
• 金额: $ 15.46万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6271076
• 关键词: algae; alternatives to animals in research; bioreactors; biotransformation; carbopolycyclic compound; chemical carcinogen; environmental contamination; heterocyclic polycyclic compound; laboratory rat; micronucleus; microorganism culture; microorganism metabolism; mixed tissue /cell culture; mutagen testing; nitrogenous heterocyclic compound; photochemistry; soil microbiology; soil pollution; toxicant screening; toxin metabolism; waste treatment

Many environments are exposed to polycyclic aromatic hydrocarbons (PAHs) and N-heterocyclic aromatics (NHAs) as complex mixtures. Specifically, 3000 former sites of coal gasification plants constitute major health hazards. The research will build upon the progress made in a) the isolation of soil microorganisms and consortia of microorganisms that degrade polyaromatic compounds and mixtures thereof, b) the characterization of the metabolic intermediates that are produced by known cultures, new isolates and consortia c) the effects of soil constituents on the bioavailability and sorption of these compounds, and d) the genotoxic effects of these compounds. This proposal targets the recalcitrant, carcinogenic 4 and 5 ring polycyclic hydrocarbons (PAHs) and the equally important N-heterocyclic aromatics (NHA). Our overall objective is to determine and enhance the microbial degradation rates of polyaromatics under simulated environmental conditions and to decrease potential health hazards associated with the PAH and NHA biodegradation products. The goal is to improve upon biodegradation and mineralization for the elimination of polyaromatic compounds and their metabolites from polluted soils. The specific aims: 1) Isolate organisms that degrade the multi-ring PAHs and NHAs from gasification sites under study using analog enrichment techniques. Compounds include further studies with BaP, benz(a)anthracene, dibenzo(c,g)carbazole, dibenz(a,j)acridine and new initiatives with chrysene and four ring acridine and carbazole derivatives. 2) Use isolated degraders of 2, 3 and 4 ring compounds singly, in mixtures as well as in contaminated soils. Metabolic intermediates, ring cleavage and reaction sequences will be investigated using both isolates and pure cultures. Studies using algae and bacteria in a cometabolic fashion to degrade large ring PAHs will also be undertaken. 3) Determine the impact of carcinogenic metals on the biodegradation of PAHs by isolated 2, 3 and 4 ring degraders. 4) Determine the extent that 2, 3, and 4 ring degrader isolates further degrade stable biodegradation products, and photooxidized products, of PAH/NHA in incubations that mimic preexposure conditions. 5) Test for the capacity of stable intermediates of biodegradation and photooxidation to induce cytogenic damage in proliferating human lymphocytes as measured by induction of micronuclei. 6) Examine the health benefit of biodegradation. This will involve determining the mutagenic activities of soil organic extracts before and after reintroduction of PAH metabolite mixtures and individual degradation products. With an understanding of the microbial hydrocarbon degradation process, strategies will be developed for utilizing microbial hydrocarbon degrading activities for the removal of toxic and carcinogenic PAHs and NHAs and their intermediates from contaminated ecosystems.

许多环境暴露于多环芳烃（PAHS） 和N-杂环芳香剂（NHAS）作为复杂的混合物。 具体来说， 3000个以前的煤气化工厂构成了主要健康 危险。 这项研究将基于A） 土壤微生物的隔离和微生物的财团的分离 降解多野型化合物及其混合物，b） 由代谢中间体的表征 已知培养物，新分离株和财团c）土壤的影响 这些化合物的生物利用度和吸附的成分，以及 d）这些化合物的遗传毒性作用。 该提议针对 顽固，致癌4和5环多环芳烃（PAHS） 以及同样重要的N-杂环芳香族（NHA）。 我们的整体 目的是确定和提高微生物降解率 在模拟环境条件下的多芳香族剂并减少 与PAH和NHA生物降解相关的潜在健康危害 产品。 目的是改善生物降解和矿化 从 污染的土壤。 具体目的：1）隔离生物降解的生物 使用类似物研究的多环PAH和NHA。 丰富技术。 化合物包括对BAP的进一步研究， Benz（A）蒽，Dibenzo（C，G）Carbazole，Dibenz（a，j）Acridine和New 用克莱森和四个环尖峰和卡唑的倡议 衍生物。 2）使用2、3和4环化合物的孤立降解器 单独地，在混合物以及被污染的土壤中。 代谢 将研究中间体，环裂解和反应序列 使用分离株和纯培养物。 使用藻类和细菌的研究 以彗星代谢的方式降解大戒指也将是 进行。 3）确定致癌金对 通过孤立的2、3和4环降解器对PAH的生物降解。 4） 确定2、3和4环降解器进一步分离的程度 降解稳定的生物降解产品和光氧化产品 pah/nha在模仿预先启动条件的孵育中。 5）测试 稳定的生物降解和光氧化中间体的能力 在测量的人类淋巴细胞增殖中诱导细胞遗传损伤 通过诱导微核。 6）检查健康益处 生物降解。 这将涉及确定诱变活动 重新引入PAH之前和之后的土壤有机提取物 代谢物混合物和单个降解产物。 与 了解微生物烃降解过程， 将制定利用微生物碳氢化合物的策略 降级活动以消除有毒和致癌的PAH和 NHA及其中间体来自受污染的生态系统。