EAGER SitS:Smart Long-Lived Biosensors for Soil Monitoring Using Engineered Spores

This collaborative project between the University of Miami and the University of Florida centers on the manufacture of novel rugged, inexpensive, long-lived sensors to safely, quickly, and reliably monitor chemical and microbial characteristics of soil for improved soil health and crop growth. These sensors are based on engineered bacterial spores that emit light only when they detect the presence of harmful chemicals and/or microorganisms in soil. These sensors can serve as an alarm to agricultural workers to protect crops from these threats. The sensors could potentially be employed widely in agricultural fields via commercialization of the newly created technology. The researchers will use the results of this project to attract and train students from diverse backgrounds in engineering. If successful, this project will provide a valuable tool to protect soil health, and in turn, help ensure the food security of the Nation. <br/><br/>This research aims to develop sensors for detecting dynamic chemical and microbial changes in soil, changes which are critical for understanding soil ecosystems and improving soil health. Whole cell biosensors (WCBs) for analytes in endospore-forming bacteria will be developed and deployed in soil to monitor chemical and microbial characteristics. The use of spores as storage elements provides a new means of preserving, packaging, transporting, storing, and using WCBs in both mild and extreme environments the field and remote locations with no easy access to laboratories. Three objectives will be undertaken to achieve the goal of the project. The first objective is to prepare WCBs for target analytes, followed by transformation into spore-forming bacteria. These biosensors will be employed in simulated agricultural fields to monitor soil chemical characteristics. For the second objective, existing WCBs for quorum sensing molecules will be incorporated into endospore-forming bacteria. The resulting biosensors will be used for determining a microbial fingerprint and optimized to monitor changes in the soil microbial ecology. The final objective is to validate the use of spore-based biosensors for soil monitoring under variable conditions in a simulated agricultural field with different types of soils. After sensing, sporulation will be induced, and the sensing spores will be kept dormant until there is need for another detection cycle. The spore sensor platform, along with state-of-the-art detection, will yield transportable, cost-effective, easy-to-use, remotely addressable or in-situ field tests. The spore sensors (1) are useful as tools for detection of soil chemical/microbial characteristics; (2) can incorporate WCBs for analyte detection; (3) are portable and rugged, capable of withstanding soil changes; (4) require no special conditions for storage and use; (5) can be buried in soil and respond to analytes when desired; (6) can be prepared at low-cost in an efficient facile manner; and (7) provide a platform for preparation, storage, transport and use of WCBs for monitoring the health of soils and plants growing in agricultural soil ecosystems. The research lends itself to education of K-12, undergraduate, graduate, and postdoctoral students in interdisciplinary research. Research progress will be disseminated through publications and presentations at conferences. Graduate students from diverse backgrounds, including those from underrepresented ethnic and socioeconomic groups, will be trained to effectively communicate to a global audience through presentation of core ideas in non-technical language. The spore sensors will be used to attract students to the STEM field through presentations in schools, museums, and science fairs. A site visit at an agricultural farm and use of sensors on-site will be incorporated in a Bionanotechnology course.<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.