CAREER: Ecosystem Processes in the Age of Antibiotics

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. <br/><br/>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.<br/><br/>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.