Ancient bacteria could improve anti-ageing cosmetics
Where better to look for a sunscreen formula than in cyanobacteria – organisms that thrived on Earth before there was enough oxygen to block harmful ultraviolet light? The genes and enzymes responsible for producing sunscreen molecules in one such cyanobacterium have now been identified, a step towards making bio-inspired sun protection.
Also known as blue-green algae, cyanobacteria have existed on Earth for 3.4 billion years. They get their energy from sunlight via photosynthesis, but in doing so, they must expose themselves to UV radiation, which damages DNA molecules – a serious problem for early life, before the “great oxygenation event” around 2.4 billion years ago. One way today’s cyanobacteria combat UV exposure is to make small-molecule sunscreens called mycosporines and mycosporine-like amino acids (MAAs) that absorb the harmful rays.