Researchers develop GM yeast to produce vitamins in bread

A group of undergraduate students have used synthetic biology to enhance common yeast that yields beta carotene, which could be baked into bread rich in vitamin A.

The team based at from John Hopkins University, USA, produced the modified yeast – known as VitaYeast – by adding a synthetic DNA plasmid ring programmed to produce beta-carotene into a common yeast cell. Research team member Ashan Veerakumar said the VitaYeast project’s goal is to design a yeast strain that synthesises essential nutrients that the human body cannot produce.

“We’re not genetically modifying the wheat here, we’re not genetically modifying the flour or the water, we’re genetically modifying 1% of the bread recipe. When you bake Vita Bread you look at it and it looks like regular bread,” explained Noah Young, a student working on the project.

"Vita Yeast is a tiny component – it gets killed in the bread," he added.

Battling malnutrition

According to the World Health Organization (WHO) vitamin A deficiency is the leading cause of preventable blindness in children.

In order to help curb global malnutrition, the research team envisioned creating an enhanced starter dough that can be easily and cheaply shared among large groups of impoverished people.

They said that the bread baked from the dough enriched with Vita Yeast could help to avert health problems that occur when vitamins and other nutrients are missing from their diets.

"The major problem in developing countries right now is not that people are hungry and starving because they don't have enough food," added Arjun Khakhar, a biomedical engineering major at John Hopkins.

"What people don't have now is the [right type of] food that they need to survive. Vital nutrients like vitamins are just missing from their diets, because they can't afford fruits and vegetables. That's what we wanted to provide through VitaYeast," he said.

Modified yeast

Team member Steffi Liu explained that they wanted to simulate the same process “that a regular person might go through to bake bread."

"The only thing that's different in the recipe is that we substituted our vitamin A yeast for the normal dry packaged yeast," she explained. The resulting bread looks exactly the same as normal bread with “definitely the same smell!”

“The lab smelled amazing after we baked the bread. Everybody wanted a bite of it. But obviously we can't do that," said Liu.

She explained the bread cannot be eaten currently because it contains a genetically engineered ingredient that has not undergone safety testing or received approval from regulators. However the group said they are encouraged by the tempting aroma and traditional bread-like texture and appearance.

GM acceptance

Despite the promise of VitaYeast, the group noted that its reception could still be hindered by public concerns about genetically modified food, including the key issues of safety and environmental impact.

“However, as technology advances and more natural resources are depleted, the impact of genetic modification will become more significant to society,” said the group.

“Therefore, in addition to our wet-lab experiments, we hope to gather data to help us understand the concerns of both the developing world and local communities regarding genetic modification and the global food supply,” they added.

The team of students, mentored by senior researchers at John Hopkins, have entered their project into the International Genetically Engineered Machine competition (iGEM), but said that no matter what happens at the iGEM finals, they will continue to develop the enhanced bread yeast as a relatively simple way to help hundreds of thousands of people who are suffering from malnutrition.