Engineering Melanin-Producing Skin Bacteria for Sun Protection

Imagine a probiotic that not only protects your skin from the harmful effects of UV radiation, but also releases antimicrobials to fight off infections and anti-inflammatory compounds to soothe irritated skin. That is the long-term goal of our proposal to engineer commensal skin bacteria to produce the natural sun protective molecule, melanin, in response to light. Advances in cellular optogenetic tools that enable light-inducible gene expression allow for the design of microorganisms that respond to light in a quantitative and tunable manner. In addition, discovery of two enzymatic routes to producing melanin, one from Malonyl-CoA and another from Tyrosine, provide a route to bioengineer organisms that produce melanin on demand. This technology could be particularly useful for soldiers who are exposed to harsh conditions that can damage the skin, as it would provide a convenient and effective way to protect against environmental hazards and skin conditions that are common in military settings. The project will leverage the state-of-the-art Synthetic Biology foundry being built at the University of California, Santa Barbara, by (1) taking advantage of its high-throughput screening and DNA synthesis capabilities to screen collections of enzymes that produce melanin and (2) utilizing its unique capabilities for culturing non-model microorganism to develop a stable human skin commensal bacterial chassis. Overall, this technology can form the basis of a platform for monitoring and responding to biotic and abiotic conditions in human skin.