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.

许多环境暴露在多环芳烃(PAHs)中 和N-杂环芳烃(NHAS)作为复杂混合物。具体来说， 3000个煤气化厂旧址构成重大健康 危险。这项研究将建立在a)取得的进展的基础上 土壤微生物的分离和微生物群的分离 降解多芳香族化合物及其混合物，b) 代谢中间产物的特征是由 已知的培养物、新的菌株和联合体c)土壤的影响 关于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效应。这项提议针对的是 顽固、致癌的4和5环多环烃(PAHs) 以及同样重要的N-杂环芳烃(NHA)。我们的整体 目的是测定和提高微生物降解率 多环芳烃在模拟环境条件下的降解性 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作用。 用于消除多芳香族化合物及其代谢产物 被污染的土壤。具体的目标是：1)分离出能降解 模拟研究中气化现场的多环多环芳烃和氨氮 浓缩技术。化合物包括对BaP的进一步研究， 苯并(A)菲、二苯并(c，g)咔唑、二苯并(a，j)吖啶和新 含有大黄素、四环吖啶和咔唑的活性物质 衍生品。2)使用2、3和4环化合物的分离降解剂 无论是在混合物中，还是在受污染的土壤中，都是如此。新陈代谢 将研究中间体、环的裂解和反应序列 使用分离株和纯培养物。利用藻类和细菌进行的研究 以共代谢的方式降解大的环状多环芳烃 承担了。3)确定致癌金属对 分离的2、3和4环降解菌对多环芳烃的生物降解4) 确定2、3和4环降解器进一步隔离的程度 降解稳定的生物降解产物和光氧化产物 PAH/NHA在模拟暴露前条件的孵化中。5)测试 生物降解和光氧化的稳定中间体的能力 诱导人淋巴细胞增殖过程中的细胞遗传学损伤 通过诱发微核。6)检查以下产品对健康的益处 生物降解。这将涉及到确定诱变活性 重新引入多环芳烃前后土壤有机提取物的变化 代谢物混合物和单独的降解产物。带着一个 了解微生物降解碳氢化合物的过程， 将制定利用微生物碳氢化合物的战略 去除有毒和致癌多环芳烃的降解活性和 NHAS及其来自受污染生态系统的中间体。