FUNGAL P450 SYSTEMS IN BIODEGRADATION OF HIGHER PAHS-R01ES15543-01

真菌 P450 系统生物降解高级 PAHS-R01ES15543-01

• 批准号: 7527777
• 负责人: Jagjit S Yadav
• 金额: $ 26.99万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7527777
• 关键词: Affect; Amendment; Ames Assay; Appearance; Aromatic Hydrocarbons; Aromatic Polycyclic Hydrocarbons; Baculoviruses; Beds; Biodegradation; Bioreactors; Bioremediations; Carbon Dioxide; Chemicals; Chrysosporium; Complex; Condition; Custom; Cytochrome P450; Development; Ecosystem; Effectiveness; Environment; Enzymes; Escherichia coli; Eukaryota; Eukaryotic Cell; Evaluation; Generations; Genes; Genetic; Goals; Health; Human; In Vitro; Kinetics; Knowledge; Laboratories; Lead; Light; Lip structure; Metabolic Biotransformation; Microsomes; Mixed Function Oxygenases; Molecular Profiling; Molecular Weight; Monitor; Numbers; Nutrient; Nutritional; Organism; Oxidases; Oxygenases; Pathway interactions; Peroxidase; Peroxidases; Phanerochaete chrysosporium; Poison; Polycyclic Hydrocarbons; Process; Production; Protein Overexpression; Proteins; Public Health; Range; Rate; Reaction; Relative (related person); Reporting; Research; Resistance; Role; Screening procedure; Site; Soil; Solid; Starvation; Substrate Specificity; System; Technology; Testing; Toxic effect; Western Blotting; Wood material; Work; Yeasts; base; catalyst; enzyme mechanism; forest; functional genomics; fungus; genotoxicity; interest; ionization; lignin peroxidase; lignocellulose; manganese peroxidase; microbial; mineralization; oxidation; pollutant; size; success; superfund site; vector; white rot fungus

DESCRIPTION (provided by applicant): Microbial biodegradation is an effective way to protect human health from polluted environments contaminated with highly toxic and carcinogenic chemicals such as polycyclic aromatic hydrocarbons (PAHs). Persistence of PAHs at these sites is due to the resistance of high m.w. PAHs (4-5 ring) to biodegradation by natural microflora. This necessitates the use of appropriate bioremediation agents and strategies that can enhance biodegradation of these recalcitrant PAHs. Our focus is on the wood-rotting white rot fungus Phanerochaete chrysosporium. Despite its extraordinary biodegradation potential, little is known on the enzymatic processes and conditions required for effective field application of this fungal agent in bioremediation of resistant PAHs in the environment. Using functional genomic approach, we have identified a subset of PAH-inducible P450 monooxygenase genes in P. chrysosporium, which are expressible under more varied nutrient conditions unlike the previously characterized peroxidases. We will test our hypothesis that an effective bioremediation activity of the white rot fungus toward higher PAHs (4-5 ring) can be achieved in a biphasic approach involving optimized initial expression of its promising P450 monooxygenases (for initial oxidation) preceding the expression of ligninolytic enzymes (for subsequent biotransformation/ mineralization to CO2) with nutrient depletion such as on lignocellulose. The overall goal of this research is to gain an understanding of the promising P450 system for use in P450-initiated biodegradation of PAHs in this organism as a basis for developing effective bioremediation strategies. The specific aims are (1) Functional expression of the candidate P450s to select the promising PAH-oxidizing P450(s) and generate P450 fungal biocatalyst(s); (2) Investigate catalytic activity of the developed P450 biocatalyst(s) and further biodegradability and toxicity reduction of the P450-oxidation products of PAHs by white rot fungus. (3) Optimize conditions for enhanced expression of the newly-identified PAH-oxidizing P450 vis-a-vis the ligninolytic peroxidases using varied treatment conditions; (4). Evaluate the optimized conditions and developed P450 biocatalysts for bioremediation of PAHs by the white rot fungus. The studies are expected to provide a knowledgebase for development of effective bioremediation technologies for recalcitrant PAHs based on the use of white rot fungus. PUBLIC HEALTH RELEVANCE: Microbial biodegradation is an effective way to protect human health from polluted environments contaminated with highly toxic and carcinogenic polycyclic aromatic hydrocarbons (PAHs). This proposal will develop appropriate fungal biocatalysts and strategies for PAH bioremediation.

描述（由申请人提供）：微生物生物降解是保护人类健康免受高毒和致癌化学物质（如多环芳烃（PAH））污染的环境污染的有效方法。 PAH 在这些地点的持久存在是由于高分子量的抵抗力。 PAH（4-5 环）可被天然微生物群生物降解。这就需要使用适当的生物修复剂和策略来增强这些顽固多环芳烃的生物降解。我们的重点是木腐白腐真菌 Phanerochaete chrysosporium。尽管其具有非凡的生物降解潜力，但人们对这种真菌剂在环境中耐药多环芳烃的生物修复中有效现场应用所需的酶促过程和条件知之甚少。使用功能基因组方法，我们在黄孢青霉中鉴定了 PAH 诱导型 P450 单加氧酶基因的子集，与之前表征的过氧化物酶不同，这些基因可在更多样化的营养条件下表达。我们将测试我们的假设，即白腐真菌对较高 PAH（4-5 环）的有效生物修复活性可以通过双相方法实现，包括优化其有前景的 P450 单加氧酶的初始表达（用于初始氧化），然后在木质素分解酶的表达（用于随后的生物转化/矿化为 CO2）和营养物消耗中，例如 木质纤维素。这项研究的总体目标是了解有前景的 P450 系统，用于 P450 引发的生物降解 PAH，作为制定有效生物修复策略的基础。具体目标是（1）候选P450的功能表达，以选择有前景的PAH氧化P450并产生P450真菌生物催化剂； (2) 研究所开发的P450生物催化剂的催化活性以及白腐真菌对PAHs的P450氧化产物的进一步生物降解性和毒性降低。 (3) 使用不同的处理条件优化条件，以增强新鉴定的 PAH 氧化 P450 相对于木质素分解过氧化物酶的表达； （4）。评估优化条件并开发 P450 生物催化剂，用于白腐真菌对 PAH 的生物修复。这些研究预计将为开发基于白腐真菌的顽固性多环芳烃的有效生物修复技术提供知识库。公共卫生相关性：微生物生物降解是保护人类健康免受剧毒和致癌多环芳烃 (PAH) 污染环境影响的有效方法。该提案将开发适当的真菌生物催化剂和多环芳烃生物修复策略。