Team:SF Bay Area DIYBio
BioSunBlock - SunScreen Evolved!
What is BioSunblock?
BioSunblock is comprised of organic compounds called Mycosporine-like amino acids (MAAs). MAAs, also known as “microbial sunscreen,” are compounds that exhibit UV-protective qualities. MAAs are naturally produced by organisms that usually live in marine environments with high amounts of UV exposure. The plan for this project is to genetically engineer bacteria to produce these compounds for sunscreen applications.
Our existing chemical sunscreens cause various health and environmental problems. Some are effective at blocking the sunburn inducing UVB rays but not the UVA rays that cause long-term skin damage. PABA was shown to induce DNA damage when applied to human skin cells in vitro and exposed to UV light, despite its UV protection of the skin from incident UV rays. PABA’s use in sunscreens has been banned in the EU since this study. Other sunscreen compounds such as oxybenzone are so toxic to coral reefs that the equivalent of a single drop in half-dozen Olympic-sized swimming pools can lead to coral bleaching - a significant issue in areas popular to beach goers and snorkelers.
Mycosporine-like amino acids (“MAAs”) are not known to be toxic to humans. In fact, many MAAs have simultaneous anti-oxidant properties in addition to their UV absorbing properties and thus may actually be beneficial in certain human conditions and when used for certain applications. They are also naturally produced by algae and corals, and should be far more friendly to the environment.
How does it work?
Our plan is to insert into E. coli a set of genes from cyanobacteria that are known to produce shinorine, one of the most common MAAs, based on prior work by Baskus and Walsh. As a side effect, this should also make the E. coli cells more resistant to UV radiation. We will then use a technique called Directed Evolution to evolve for increased UV resistance, thereby optimizing shinorine production in E. coli or potentially even evolving novel alternative mycosporine-like amino acids. Finally, we will sequence the resulting genes to figure out what changes have occurred that improved our engineered construct.