Who you gonna call?

If there's something strange in you neighborhood
Who you gonna call?
If there's something weird
And it don't look good
Who you gonna call?

Every summer's day (and even the first days of spring) brings the same problem to me. SUNBURNS! I have yet to find a sunscreen that doesn't become super sticky within minutes - especially on the beach. Sunscreen and sand are simply a terrible match! But I don't want to leave out the sunscreen, get painful sunburns and even increase my risk of skin cancer. 

Who am I going to call to solve my problems?! Well, maybe in the future, bacteria will be the heroes answering my call!

The first responders to my call could be cyanobacteria, known to most people as blue-green algae. They are notorious for contaminating waterbodies and releasing harmful toxins that make swimming in them dangerous. The name blue-green algae is misleading, because the diverse microorganisms collected under that name, are bacteria, not plants. Not just any bacteria though, but bacteria that can do photosynthesis, just like plants. 

In order to do photosynthesis (using energy from light to generate energy-rich biomolecules), cyanobacteria must expose themselves to the sunlight and absorb it. Just like our DNA is at risk of being damaged by the UV-wavelength in the sunlight, so is the cyanobacteria's DNA.
To protect their DNA, cyanobacteria can produce small molecules called mycosporine-like amino acids (MAAs) that absorb the UV light. Current sunscreens contain synthetic UV-absorbers, but they cause allergic reactions for many people. MAAs could be an alternative to give UV-absorbing properties to the sunscreen [1]. As with many biotechnological compounds, the production conditions of MAAs must be optimized to increase the yield for industrial production. Currently, two different synthesis pathways for MAAs have been described [2], leaving lots of options for boosting industrial MAA production.

The next "Mic'd up" post will explain, which bacteria could be answering your call when it is already too late to protect you from skin cancer. Until then: enjoy the sun & don't get burnt!

Resources:
Review of cyanobacterial metabolites that inspired me to write this post:
https://www.tandfonline.com/doi/full/10.1080/09670262.2016.1214882 (open access)
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866486/ (open-access)
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3901267/ (open access)