Biodiversity and Hydrocarbon Degradation Capacity of Marine Fungi

海洋真菌的生物多样性和碳氢化合物降解能力

• 批准号: RGPIN-2017-04325
• 负责人: Walker, Allison
• 金额: $ 1.89万
• 依托单位: Acadia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667975
• 关键词: Biodiversity; Hydrocarbon; Degradation; Capacity; Marine

I am interested in the biodiversity of marine fungi and in their ability to degrade hydrocarbons. I am more specifically interested in the species of fungi that grow naturally in the Bay of Fundy and its fringing saltmarshes (eastern Canada) and the extent to which they have natural resilience to marine oil spills. My lab is approaching this problem by first characterizing the diversity of marine fungi from the water column and coastal sediments using morphological and molecular methods (DNA barcoding). We will then use selective media with marine fuel oil as sole carbon source to isolate potential hydrocarbon-degrading fungi. These experiments will allow us to assess the mass loss of crude oil, and provide proof of metabolism of hydrocarbons (C14 naphthalene degradation to CO2). They will also help determine which marine fungi possess cytochrome P450 monooxygenases (P450s), which fungi use to degrade hydrocarbons. Approaches for identifying and quantifying P450s from novel fungal isolates and environmental samples will include protein identification via liquid chromatography-orbitrap tandem mass spectrometry (LC-MS/MS) and quantification via liquid chromatography-selected reaction monitoring mass spectrometry (LC-SRM). This work will be done in collaboration with Dr. Erin Bertrand (Dalhousie Tier II CRC in Marine Microbial Proteomics). ***Preliminary work in my lab has identified candidate strains from Nova Scotia seawater that allow us to investigate if prior exposure to oil increases oil degradation rates by marine fungi. We also intend to study candidate fungal strains singly and in mixed-species consortia to examine the effects of nutrient supplementation and temperature on oil degradation rates. We will use our proteomics approach to explore interactions between native oil degrading fungi and the existing Bay of Fundy microbial community (inhibition or promotion of degradative enzyme production) under different temperature and nutrient regimes. ***We are characterizing this poorly known component of coastal systems to explore the role that fungi play in the resilience to marine oil spills of the Bay of Fundy ecosystem. My lab is the first to take a molecular ecology approach to understanding the biodiversity and oil degrading capacity of marine fungi. In the process, we will also begin to uncover the evolutionary relationships of marine fungi, improving our reference databases for DNA-based fungal identifications, and training students in cutting edge molecular phylogenetics and proteomics approaches. We expect to describe many new species of fungi as we shed light on marine fungal biodiversity and ecological function in northern coastal ecosystems. My work will have broad implications for remediation of oil spills in coldwater marine ecosystems, and for understanding the evolution of fungal cytochrome P450s.

我对海洋真菌的生物多样性及其降解碳氢化合物的能力感兴趣。我更特别感兴趣的是在芬迪湾及其边缘盐沼（加拿大东部）自然生长的真菌种类，以及它们对海洋石油泄漏的自然恢复能力。我的实验室正在解决这个问题，首先使用形态学和分子方法（DNA 条形码）表征水柱和沿海沉积物中海洋真菌的多样性。然后，我们将使用以船用燃油作为唯一碳源的选择性培养基来分离潜在的碳氢化合物降解真菌。这些实验将使我们能够评估原油的质量损失，并提供碳氢化合物代谢的证据（C14 萘降解为二氧化碳）。他们还将帮助确定哪些海洋真菌拥有细胞色素 P450 单加氧酶 (P450)，真菌利用这些酶来降解碳氢化合物。从新型真菌分离株和环境样品中识别和定量 P450 的方法包括通过液相色谱-orbitrap 串联质谱 (LC-MS/MS) 进行蛋白质鉴定，以及通过液相色谱选择反应监测质谱 (LC-SRM) 进行定量。这项工作将与 Erin Bertrand 博士（达尔豪斯海洋微生物蛋白质组学二级 CRC）合作完成。 ***我的实验室的初步工作已经确定了来自新斯科舍省海水的候选菌株，使我们能够调查之前接触石油是否会增加海洋真菌的石油降解率。我们还打算单独研究候选真菌菌株和混合物种菌群，以检查营养补充和温度对油降解率的影响。我们将利用蛋白质组学方法探索不同温度和营养条件下天然石油降解真菌与现有芬迪湾微生物群落之间的相互作用（抑制或促进降解酶的产生）。 ***我们正在描述沿海系统这一鲜为人知的组成部分，以探索真菌在芬迪湾生态系统应对海洋石油泄漏的能力中所发挥的作用。我的实验室是第一个采用分子生态学方法来了解海洋真菌的生物多样性和石油降解能力的实验室。在此过程中，我们还将开始揭示海洋真菌的进化关系，改进基于 DNA 的真菌鉴定的参考数据库，并培训学生使用尖端的分子系统发育学和蛋白质组学方法。当我们阐明北部沿海生态系统的海洋真菌生物多样性和生态功能时，我们期望描述许多新的真菌物种。我的工作将对冷水海洋生态系统中石油泄漏的修复以及了解真菌细胞色素 P450 的进化产生广泛的影响。