NUS Researchers Develop Multi-Color Light-Controlled Yeast

Researchers at the National University of Singapore have developed a yeast strain that can respond independently to different colors of light, opening possibilities for more precise control of yeast-based biomanufacturing processes.

Baker’s yeast is widely used for bread leavening and fermentation, while advances in synthetic biology have expanded its potential as a microorganism for producing ingredients, chemicals, fuels and pharmaceutical compounds.

The NUS research team, led by Associate Professor Poh Chueh-Loo from NUS Synthetic Biology for Clinical and Technological Innovation and the Department of Biomedical Engineering, used optogenetics to control selected genes in yeast through different colors and patterns of light.

Optogenetics allows biological processes to be switched on or off using light rather than repeatedly introducing chemical inducers. According to the researchers, the approach could make yeast-based manufacturing processes more predictable and programmable.

Poh Chueh-Loo stated: “Achieving precise, dynamic control over cellular machinery has been a goal in synthetic biology, […] By using different colors of light to dictate complex, multi-step processes, we are paving the way to make biological manufacturing more predictable and programmable.”

While yeast has previously been engineered to respond to individual colors, the researchers said their work marks the first time a single yeast strain has been engineered to respond to more than one color.

One of the main developments was a red light-responsive protein for yeast called y-iLight. When exposed to red light, the protein binds to specific DNA sequences and activates selected genes. The system does not require additional chemicals beyond those naturally present in yeast, which the researchers said could make it simpler and more cost-effective for practical applications.

The researchers subsequently addressed interference from blue light by modifying y-iLight and combining the resulting system with EL222, an established blue light-responsive system. This allowed the team to independently control two gene-expression channels within the same yeast strain.

To demonstrate the technology, the researchers placed two enzymes involved in producing luteolin, a naturally occurring plant compound, under separate red and blue light controls. By changing the timing and proportions of the two colors, they were able to adjust the yeast’s production process.

The team also demonstrated that light could control yeast behavior. Researchers linked the FLO1 flocculation gene, which causes yeast cells to stick together, to a red light-activated switch. The yeast first produced luteolin under blue light before red light was used to trigger the cells to clump together and sink.

According to NUS, the experiment demonstrates the potential to use light to control both production and subsequent separation processes, which could contribute to cleaner and more programmable biomanufacturing.

“Together, the work shows that yeast can be programmed with multiple colors of light to control gene expression, metabolic pathways, cell behavior and spatial patterning,” Poh said. “The platform could support future applications in biomanufacturing, pathway optimization and living materials.”

The research was published in Nature Communications on May 22, 2026. The NUS team is continuing to develop technology, with current work focused on strengthening the performance and sensitivity of the light-responsive proteins for potential future microbial manufacturing applications.