Shown above are KAIST scientists of Dr. Park Seon-young Park at KAIST, left, and Ph.D. candidate Eun Hyun-min. They have developed a new way of making lutein. Photo courtesy of KAIST

Metabolically-engineered bacterium comes up with lutein

A group of Korea Advanced Institute of Science and Technology (KAIST) researchers have engineered a bacterial strain capable of producing lutein, according to the ivory tower on Aug. 17.

The research team headed by Prof. Lee Sang-yup applied systems metabolic engineering strategies, including substrate channeling and electron channeling, to enhance the production of lutein in an engineered Escherichia coli strain.

KAIST noted that the strategies would also be useful for the efficient production of other industrially important natural products used in the food, pharmaceutical, and cosmetic industries.

Lutein is classified as a xanthophyll chemical that is abundant in egg yolk, fruits, and vegetables. It protects the eye from oxidative damage from radiation and reduces the risk of eye diseases, including macular degeneration and cataracts.

Commercialized products featuring lutein are derived from the extracts of the marigold flower, which is known to harbor abundant amounts of lutein.

However, the drawback of lutein production from nature is that it takes a long time to grow and harvest marigold flowers. Furthermore, it requires additional physical and chemical-based extractions with a low yield, which makes it economically unfeasible in terms of productivity.

The high cost and low yield of these bioprocesses have made it difficult to readily meet the demand for lutein.

KAIST said that these challenges inspired its engineers of Dr. Park Seon-young Park, Ph.D. candidate Eun Hyun-min, and Prof. Lee .

The team’s study entitled “Metabolic engineering of Escherichia coli with electron channeling for the production of natural products” was published in Nature Catalysis on Aug. 5, 2022.

“It is expected that this microbial cell factory-based production of lutein will be able to replace the current plant extraction-based process,” Dr. Park said as the first author of the paper.

She commented that another important point of the research is that integrated metabolic engineering strategies developed from this study can be generally applicable for the efficient production of other natural products useful as pharmaceuticals or nutraceuticals. 

“As maintaining good health in an aging society is becoming increasingly important, we expect that the technology and strategies developed here will play pivotal roles in producing other valuable natural products of medical or nutritional importance,” Prof. Lee said.