Abstract

Measuring metabolites produced by large libraries of metabolically engineered yeast requires high throughput screening technology. Current screening methods use mass spectrometry to measure metabolites. Higher throughput detection methods are available, however they rely on fluorescent detection. Measuring non-fluorescent metabolites requires an alternative detection method integrated in the screening system. Herein, we introduce an electrochemical sensor, that can be integrated with droplet microfluidics to detect a key branch point molecule in opiate biosynthesis: (S)-reticuline, which is produced by metabolically engineered yeast. This platform technology could be used to screen a heterogenous library consisting of engineered yeast that secrete (S)-reticuline. Demonstrating that yeast cells in a population, which produce high titers of (S)-reticuline can be detected using this screening system will open the door to screening libraries of micro-organisms that produce other electroactive, non-fluorescent secreted metabolites.