It is routine to trigger the production of a protein in engineered E. coli using a small molecule such as arabinose, lactose, and rhamnose. Our project is focused on answering the question, “Can sound be used to induce gene expression in engineered E. coli?” Prior iGEM projects demonstrated that sound can be used to activate eukaryotic cells. Review of the scientific literature revealed projects where exposing E. coli to sound correlated with more vigorous growth in cell cultures and increased production of proteins.

In 2008, the University of California, Berkeley (UC Berkeley) iGEM team contributed five genetic parts to the iGEM community. The genetic parts were derived from DNA sequences found upstream from genes that were potentially upregulated when the cells were exposed to sound. The UC Berkeley iGEM team was unable to demonstrate definitively that the genetic parts could be used as sound inducible promoters of gene expression. We decided to build on their work. We designed, built, and tested new genetic devices using the Berkeley promoters that were intended to detect sound and stimulate the expression of reporter proteins.

Members of the FSU iGEM team also investigated genes that were up-regulated when exposed to sound, according to other scientific literature. These signaling pathways and promoters were then analyzed and used to build new genetic devices which included reporter proteins that signal different levels of expression. Our new cells were tested at different sound frequencies and amplitudes to see which cells reported the highest level of reporter protein expression.

Audio induction has many possible impacts, the limit to which is still unclear. Our Human Practices team started a discussion in the fields of molecular biology, brewery, and law enforcement to explore the potential positive and negative impacts of using sound to induce gene expression.