MICROBIAL DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBON MIXTURES

多环芳烃混合物的微生物降解

• 批准号: 6340902
• 负责人: DAVID WARSHAWSKY
• 金额: $ 17.11万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6340902
• 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.

许多环境都暴露于多环芳烃 (PAH) 和 N-杂环芳烃 (NHA) 作为复杂混合物。 具体来说， 3000座煤气化厂旧址构成重大卫生事件 危险。 该研究将建立在以下方面取得的进展的基础上： 土壤微生物和微生物群落的分离 降解多芳香族化合物及其混合物，b) 产生的代谢中间体的表征 已知的文化、新的分离物和菌群 c) 土壤的影响 成分对这些化合物的生物利用度和吸附的影响，以及 d) 这些化合物的遗传毒性作用。 该提案的目标是 顽固、致癌的 4 环和 5 环多环烃 (PAH) 以及同样重要的 N-杂环芳烃 (NHA)。 我们的整体 目标是确定和提高微生物降解率 模拟环境条件下的聚芳烃并减少 与 PAH 和 NHA 生物降解相关的潜在健康危害 产品。 目标是改善生物降解和矿化 用于消除多环芳烃化合物及其代谢物 被污染的土壤。 具体目标： 1) 分离降解有机物的生物体 使用模拟方法研究来自气化场的多环 PAH 和 NHA 浓缩技术。 化合物包括 BaP 的进一步研究， 苯并(a)蒽、二苯并(c,g)咔唑、二苯(a,j)吖啶及新 与屈和四环吖啶和咔唑的倡议 衍生物。 2) 使用2、3和4环化合物的分离降解剂 单独、混合物以及受污染的土壤中。 代谢 将研究中间体、环裂解和反应序列 使用分离物和纯培养物。 使用藻类和细菌的研究 以共代谢方式降解大环多环芳烃也将 进行。 3) 确定致癌金属对人体的影响 通过分离的 2、3 和 4 环降解剂对 PAH 进行生物降解。 4） 确定 2、3 和 4 环降解剂进一步隔离的程度 降解稳定的生物降解产物和光氧化产物 模拟暴露前条件的培养中的 PAH/NHA。 5) 测试 稳定的生物降解和光氧化中间体的能力 根据测量，在增殖的人类淋巴细胞中诱导细胞源性损伤 通过微核的诱导。 6) 检查对健康的益处 生物降解。 这将涉及确定诱变活性 重新引入 PAH 前后土壤有机提取物的变化 代谢混合物和单独的降解产物。 与一个 了解微生物碳氢化合物降解过程， 将制定利用微生物碳氢化合物的策略 去除有毒和致癌多环芳烃的降解活性 来自受污染生态系统的 NHA 及其中间体。