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Bio Sun Block (Evolved Bacterial Sunscreen)

Introduction

No, not sunscreen for bacteria - sunscreen made by bacteria. We are going to make e.coli bacteria create shinorine, a UV absorbing compound that is currently being extracted from algae as an eco-friendly susnscreen.

Genetic Engineering is arguably the greatest leap forward in human understanding and manipulation of nature in the whole history of mankind, above and greater than the invention of fire and the wheel combined. This project makes use of Genetic Engineering to force a bacteria to create a compound that it would never make and then use the tools of evolution to enhance that ability.

E.coli can easily be killed by UV light. By equipping it with the genes to produce UV absorbing compounds, we expect that the E. coli will become somewhat UV resistant as well. After designing the process, we want to make it better, so we will employ “directed evolution” to make the process better. We think that if we stress the bacteria with UV that they will start to evolve better and more efficient mechanisms to protect themselves from UV.

So that is our project: start some bacteria making sunscreen then subject them to a lot of sunshine and they will evolve to make more and better sunscreen.

What is sunscreen

Sunscreens are chemical compounds that absorb or reflect UV thus preventing the UV from damaging cells. We tend to put sunscreen on our skin to protect the underlying skin cells from sunlight mostly UV. Sunscreen will absorb specific UV spectrum, the more (wider) the UV spectrum the better the effect of the sunscreen. Each chemical compound will absorb a part of the spectrum therefore it is best to have several different UV absorbing chemicals.

Mycosporine

Mycosporine-like amino acids (MAAs) are small secondary metabolites produced by organisms that live in environments with high volumes of sunlight, usually marine environments. So far there are up to 20 known MAAs identified. They are commonly described as “microbial sunscreen” but their function is not limited to sun protection.

Though most MAA research is done on their photo-protective capabilities, they are also multifunctional secondary metabolites that have many cellular functions. MAAs are effective antioxidant molecules and are able to stabilize free radicals within their ring structure. In addition to protecting cells from mutation via UV radiation and free radicals, MAAs are able to boost cellular tolerance to desiccation, salt stress, and heat stress.

Physics of sunscreen

The Sun Protection Factor (SPF) rating of sunscreen essentially measure how much longer it allows someone to stay in the sun before getting a sunburn caused by UV-B light (290-320 nanometers). This is an imperfect measure of skin damage because invisible damage and skin aging are also caused by ultraviolet type A (UV-A, wavelengths 320–400 nm), increasing the risk of malignant melanomas.

UV rays carry high energy and are suspected of causing cancer through damage to the skin's DNA. High energy in sunlight comes in two forms:

UV-A (320-400 nanometers)

UV-B (290-320 nanometers)

The UVB waves tend to receive more criticism than the less energetic UVA waves.

But, in actual fact, both UVB and UVA can damage the skin. Unfortunately, the chemistry of sunscreen, in most cases, does not enable the blocking of UVA as effectively, if at all, as they do UVB.