ADVANCING ECOTOXICOLOGY, FOOD SCIENCE, WILDLIFE ECOLOGY, SOIL BIOGEOCHEMISTRY, AND MICROBIAL ECOLOGY USING COMPOUND-SPECIFIC CARBON AND NITROGEN ISOTOPES ANALYSIS

我们的研究团队旨在利用化学示踪剂，通过自然生态系统和人类管理的食物系统，从微生物到顶级捕食者，了解能量、营养物质和污染物的运动和命运。该方法最近的一个主要进展是化合物特异性同位素分析（CSIA），例如氨基酸同位素分析和脂肪酸同位素分析。我们正在为CSIA所需的设备寻求RTI资金：气相色谱仪与同位素比质谱仪（GC-IRMS）接口。该系统将提供关键的新的高分辨率示踪数据，加速Melissa McKinney， Nil Basu, Stephane Bayen, Jessica Head, Kyle Elliott, Cynthia Kallenbach， Denis Roy和Lyle Whyte的研究项目。****** CSIA方法显示出在传统上依赖于大量同位素分析的示踪剂应用中成为有价值的工具的潜力。例如，由于某些氨基酸的氮同位素比率在食物网中是保守的，而其他氨基酸则显示出营养富集，因此氨基酸同位素分析已被证明比大量氮同位素提供了更好的营养位置指示。通过GC-IRMS，我们的研究小组将领导尖端CSIA技术的开发和应用，以识别和量化农业和自然生态系统在多个分类、空间和时间尺度上的途径和变化。****** GC-IRMS是麦吉尔大学农业与环境科学学院多个研究小组的关键组成部分。McKinney、Basu和Head将使用GC-IRMS生成新的高分辨率数据，促进在了解污染物暴露的种内、种间、空间和时间变化方面取得关键进展。Bayen将使用GC-IRMS来评估食品来源欺诈。艾略特将使用该系统来检查食物网结构及其与污染物的关系。Kallenbach将用它来了解全球变化因素，如变暖、洪水、农业管理，如何影响土壤氮动态。罗伊建议用它来评估适应加拿大北极盆地不同海洋栖息地的北极海洋鱼类的饮食差异。Whyte将使用GC-IMRS识别和跟踪在不同温度和盐度下生长的极地微生物菌株中氨基酸和脂肪酸同位素的变化，以确定生活在低温环境中的微生物的微生物适应性。******我们的20名或更多的学生将在这个最先进的科学系统的实践技能方面具有明显的竞争优势，包括其使用，维护，质量保证/质量控制以及同位素数据处理。更广泛地说，加拿大的各个科学领域都采用气相色谱和质谱作为分析工具；因此，这种实践培训为学生提供了在农业和环境科学领域未来学术、政府、工业和非营利职业中取得成功的市场技能。*****

Our research team aims to understand the movement and fate of energy, nutrients, and contaminants through natural ecosystems and human-managed food systems, from microbes to top predators, using chemical tracers. A major recent advance in this approach is compound-specific isotopes analysis (CSIA), e.g., amino acid isotopes analysis and fatty acid isotopes analysis. We are seeking RTI funds for the equipment needed for CSIA: a gas-chromatograph interfaced to an isotope ratio mass spectrometer (GC-IRMS). This system will provide crucial new high-resolution tracer data accelerating the research programs of Melissa McKinney, Nil Basu, Stephane Bayen, Jessica Head, Kyle Elliott, Cynthia Kallenbach, Denis Roy, and Lyle Whyte. ******The CSIA approach shows potential to be a valuable tool in tracer applications, which have traditionally relied on bulk isotopes analysis. For example, as nitrogen isotope ratios of certain amino acids are conserved through the food web, while others show trophic enrichment, amino acid isotopes analysis has been shown to provide a better indication of trophic position than bulk nitrogen isotopes. With the GC-IRMS, our research groups will lead the development and application of cutting-edge CSIA techniques to identify and quantify pathways and changes in agricultural and natural ecosystems across multiple taxonomic, spatial, and temporal scales.******The GC-IRMS represents a key component of multiple research groups within the Faculty of Agricultural and Environmental Sciences at McGill University. McKinney, Basu, and Head will use the GC-IRMS to generate new high-resolution data fostering critical advances in understanding intra-specific, inter-specific, spatial, and temporal variation in contaminant exposures. Bayen will use the GC-IRMS to assess food origin fraud. Elliott will use the system to examine food web structures and their associations with contaminants. Kallenbach will use it to understand how global change factors, e.g., warming, flooding, agricultural management, influence soil nitrogen dynamics. Roy proposes to use it to assess diet differences in Arctic marine fish species adapted to different marine habitats across Canadian Arctic basins. Whyte will use the GC-IMRS to identify and track shifts in amino acid and fatty acid isotopes in polar microbial strains growing at different temperatures and salinities to determine microbial adaptations of microorganisms living in cryoenvironments.******Our 20 or more students will have a clear competitive advantage with hands-on skills in this state-of-the-science system, including its use, maintenance, quality assurance/quality control, and in isotope data processing. More broadly, various scientific fields in Canada employ GC and MS as analytical tools; thus, such hands-on training provides marketable skills for students to succeed in future academic, government, industry, and non-profit careers across the agricultural and environmental sciences.*****