Cell free biosensors for detection of contaminants in waters of the Matanza Riachuelo Basin

VILLARRUEL DUJOVNE, MATIAS; SOFIA LIUBOSCHITZ; LAUREN CLARKE; JULIUS LUCKS; MICHAEL JEWETT; DAIANA CAPDEVILA

Congreso; SAIB SAMIGE Congreso Conjunto 2021; 2021

Water quality assessment is an issue of global relevance. Locally, 15% of Argentina?s population inhabits the Matanza-Riachuelo Basin, whose natural and superficial waters have been found to not be apt for human use or consumption due to the presence of natural (ie. arsenic) or anthropogenic (ie. transition metals) pollutants. Monitoring the presence of these contaminants along the basin by local authorities is limited due to the need of specific, expensive, and non-transportable equipment. Recent advances in cell-free synthetic biology have spurred the development of in vitro molecular diagnostics. Here, we present the work done in fine tuning two cell free based biosensors. Both systems can be freeze dried for easy storage and distribution making them a perfect choice as inexpensive point of use water quality assessment devices.First, we report the advances done on a cell-free in vitro transcription platform, aptly named ROSALIND. This is a modular system that combines a highly processive RNA polymerase, allosteric transcription factors and synthetic DNA transcription templates to regulate the synthesis of a fluorescence-activating RNA aptamer in presence of a target contaminant. The platform has been validated to detect a range of water contaminants. Here we focus on our recent work of tuning the reaction to detect relevant pollutants in the basin in collaboration with the local authority ACUMAR.More recently, we are working to incorporate a new generation of biosensors based on cell free protein expression on bacterial lysates that will allow us to widen the range of contaminants we can detect to other common ones such as arsenic and nitrates. Cell lysates-based biosensors allow us to forgo the need to add purified components, decreasing the price and labor cost of individual reactions. The signal can be easily amplified thus allowing for low detection limits. Here we present the first steps on preparing the cells extracts and validating their quality for later use in sensors.