CAREER: Ecosystem Processes in the Age of Antibiotics

1928年，亚历山大·弗莱明发现了青霉素的抗生素特性。自从这一发现以来，抗生素一直是人类健康和农业牲畜生产的福音。事实上，后者使用了美国生产的80%的抗生素，每年惊人的3300万磅。这些抗生素和抗生素衍生物中的大多数最终进入环境，导致断言地球上没有一个环境不受农业抗生素的影响。尽管如此，很少有研究审查农业抗生素可能对环境产生的影响，例如对土壤微生物群落及其介导的生态系统过程的影响。这项研究将确定抗生素对土壤食物网和生态系统过程的影响，无论是现在还是在不确定的未来。在研究抗生素对环境的影响的同时，该项目将包括研究生和博士后水平的培训，并开发一个真实的，远征式的课程，可以跨多所中学整合，使学生积极参与研究。通过调查、实地和实验室实验，本研究将确定：1)土壤抗性组的生物地理模式（即抗生素抗性基因的收集和多样性）；2)抗生素对土壤食物网和生态系统过程的影响；3)抗生素投入与温度变化的相互作用。土壤微生物群落对陆地生态系统的健康运作至关重要。然而，这些群落可能受到外源来源的抗生素投入的显著影响。例如，抗生素的投入可能会改变微生物效率，导致生态系统碳和养分保持降低，影响土壤食物网结构和群落相互作用，并可能影响土壤微生物群落对全球环境变化的响应。这项研究旨在调查抗生素投入对陆地生态系统的潜在重要作用，但研究不足。此外，本研究旨在更好地了解特定土壤群落和生态系统功能对抗生素扰动的敏感性。这项研究的结果将使我们更全面地了解抗生素投入对土壤群落结构和功能的潜在影响，以及这些投入在未来的意义。除了培养一名研究生和博士后研究员外，该项目的教育部分还将使中学生接触到旨在增加他们对土壤、微生物和生态系统生态学知识的多个课程模块。中学生是一个处于决定其终身职业目标的关键时刻，但往往不积极参与科学研究的学生群体。这些年轻学生也将积极参与项目，收集数据并进行与项目科学目标直接相关的研究。总体而言，该项目将阐明抗生素对环境的影响，同时也为中学生的科学发现提供基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In 1928, Alexander Fleming identified the antibiotic properties of penicillin. Since this discovery antibiotics have been a boon for human health as well as for agricultural livestock production. In fact, the latter utilizes 80% of the antibiotics produced in the United States, a staggering 33 million pounds a year. Most of these antibiotics and antibiotic derivatives ultimately enter the environment, leading to the assertion that no environment on earth is free from the influence of agricultural antibiotics. Despite this, little research has examined the environmental influence agricultural antibiotics are likely to have, for example, on soil microbial communities and the ecosystem processes they mediate. This research will determine the effect antibiotics have on soil food webs and ecosystem processes both now and in an uncertain future. While examining the environmental implications of antibiotics, this project will include training at the graduate student and postdoctoral levels, and develop an authentic, expeditionary style curriculum that can be integrated across multiple middle schools which enables students to actively participate in research. Using a combined set of survey, field, and lab experiments this research will determine: 1) biogeographic patterns of the soil resistome (i.e. the collection and diversity of antibiotic resistance genes); 2) the implications of antibiotics for soil food webs and ecosystem processes; and 3) the interaction between antibiotic inputs and temperature changes. Soil microbial communities are central to the healthy functioning of terrestrial ecosystems. However, these communities are likely to be markedly affected by antibiotic inputs derived from exogenous sources. For instance, antibiotic inputs may alter microbial efficiency leading to lower ecosystem carbon and nutrient retention, affect soil food web structure and community interactions, and potentially influence the response of soil microbial communities to global environmental change. This research is designed to investigate the potentially important, but under-studied, role antibiotic inputs have on terrestrial ecosystems. Additionally, this research seeks to better understand the susceptibility of particular soil communities and ecosystem function to antibiotic perturbation. The results gained from this research will lead to a more complete understanding of the potential impact antibiotic inputs have on soil community structure and function, and the implication of these inputs in the future. In addition to training a graduate student and postdoctoral researcher, the educational component of this project will expose middle school students -- a student population that is at a critical juncture in deciding their lifetime career objectives, but often not actively engaged in science -- to multiple curricular modules that aim to increase their knowledge of soil, microbial, and ecosystem ecology. These young students will also be active participants in the project by collecting data and conducting research directly related to the scientific objectives of this project. Overall this project will elucidate the environmental implications of antibiotics while also providing a foundation in scientific discovery for middle school students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.