St. Petersburg College Honors Program students Roberta Spathari (Chemical Engineering) and Erin Hoyle (Microbiology) authored the following research on finding a new pigment that could be used for future organic based sun protection.

In January 2014, we became members of MRSA (Microbiology Research Student Association), a club at St. Petersburg College Clearwater Campus, whose advisor is Dr. Shannon Ulrich.

After researching the use of bacterial pigments in different products, we discovered a company in Norway called Promar AS that believes an organic alternative synthesized by bacteria will be the future of sun protection.

Promar AS suggests Micrococcus luteus, which produces a pigment that can absorb long-wavelength UV radiation, is the most promising bacterium. We decided to base our research in finding a new microbial pigment that could be used for future organic based sun protection and will be able to replace harmful carcinogenic chemicals that are currently in most sunscreens in today’s market.  We have isolated several microbes that produce pigments and our research has focused on assessing the light absorption properties of the pigments produced by these microbes.

In our experiment, we tested the resiliency to ultraviolet (UV) light on more than 30 species of microbes.  We determined the microbes that could survive long exposure times to direct ultraviolet radiation were more likely to contain protective pigments. In our experiments, two species of microbes that survived the longest exposure times were Micrococcus luteus and an unknown pink yeast.  Interesting, after 12 minutes of UV radiation, the pink yeast had 24 times the amount of growth as the species used by Promar AS, Micrococcus luteus.

We used a solvent extraction method to extract the pink pigment from the yeast to asses its ultraviolet absorbing properties. The pink yeast actually absorbed an average of 96% of the ultraviolet light at 280 nanometers. This is equivalent to the absorption properties of 30 SPF sunscreen.

Sun protection research presented at science conferences

Our research was selected to be presented in many science conferences including:

• The annual Florida Branch of the American Society for Microbiology conference held in Cocoa Beach
• SPC Annual Collegiate Research Conference
• 2016 Florida Collegiate Honors Council Conference
• Southern Regional Honors Council

During our time at the honor’s conference, the atmosphere was extremely positive and encouraging for all students. We made many contacts and heard feedback from other science focused students around the country. The overwhelming support from our peers at these conferences actually helped push us to submit a patent proposal for our research.

Learn more about SPC’s Honors Program.