Korea Advanced Institute of Science and Technology (KAIST) researchers successfully engineered Escherichia coli to produce all seven colors of the rainbow. Their findings are published in Advanced Science.

Most colorants used in food, cosmetic, chemical, and pharmaceutical industries are made of petroleum, which can pose side effects to humans and risks to the environment. This led KAIST researchers to explore using microbes to develop safer, natural colorants. They focused on engineering the metabolism of E. coli to efficiently produce seven natural pigments. The pigments accumulate inside the cells of the bacterium, which has limited storage capacity. Thus, the team engineered the cell share and came up with tiny sacs within to boost the cell's capacity for pigments. Tiny sacs on the outside part of the cell were also developed to secrete pigments.

The results of the study can help food, pharmaceutical, and cosmetic industries efficiently produce natural colorants that can replace petroleum-based synthetic colorants.

Read the articles in Advanced Science and Asian Scientist.