Biodiversity and Hydrocarbon Degradation Capacity of Marine Fungi

我对海洋真菌的生物多样性和它们降解碳氢化合物的能力很感兴趣。我特别感兴趣的是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，首先用形态学和分子方法（DNA条形码）描述水柱和海岸沉积物中海洋真菌的多样性。然后，我们将使用以海洋燃料油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（C14萘降解为二氧化碳）的证据。它们还将有助于确定哪些海洋真菌拥有细胞色素P450单加氧酶（P450），真菌利用这种酶降解碳氢化合物。从新的真菌分离物和环境样品中鉴定和定量p450的方法将包括通过液相色谱-轨道阱串联质谱（LC-MS/MS）和通过液相色谱-选择反应监测质谱（LC-SRM）进行蛋白质鉴定。这项工作将与Erin Bertrand博士（Dalhousie Tier II CRC在海洋微生物蛋白质组学）合作完成。

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.