Mark Styczynski Ph.D. (ChBE/Georgia Institute of Technology)
Andreas Bommarius, Ph.D. (ChBE/Georgia Institute of Technology)
Brian Hammer, Ph.D. (Biology/Georgia Institute of Technology)
Hang Lu, Ph.D. (ChBE/Georgia Institute of Technology)
Pamela Peralta-Yahya, Ph.D. (Chemistry/Georgia Institute of Technology)
Engineering a Fast-Responding Bacterial Test for Zinc Deficiency
Zinc deficiency is estimated to affect millions of children each year, but the high cost and logistical challenges associated with current zinc diagnostic tools prevent adequate surveillance and treatment of zinc deficiency. To be used in surveillance programs, a zinc status diagnostic test must be inexpensive, easy to administer, nearly equipment-free, and fast-responding. A bacterial biosensor has the potential to meet all of these requirements. Our group recently developed a low-cost E. coli biosensor that can produce different visible outputs based on the concentration of zinc in which the cells grow. However, these initial sensor cells always produce some pigment, which necessitates that they be grown from a very small inoculum so that initial coloration is minimal – thus requiring overnight assay times. To make an easy-to-use, field-deployable assay, we will engineer cells to repress pigmentation during growth and to quickly produce pigments from either the carotenoid or violacein pathways upon induction. Zinc-responsive elements will also be tested in a lysate based cell-free system, and both the whole cell and cell-free systems will be tuned to respond to physiologically relevant serum zinc concentrations. The resulting biosensor will be a significant step towards a deployable, field-friendly zinc diagnostic tool.