Honey bees are responsible for helping feed the world, pollinating approximately every third bite of food eaten globally. Yet these essential pollinators are under serious and multiple stressors that put their survival at risk. In the United States, commercial honey bee colony losses have averaged between 40 and 50% annually over the past ten years. Yet experts today are warning that this shocking statistic may jump to 60% to 70% in 2025. To help reverse this disturbing trend, scientists, supported by the Foundation’s research grant program, have engineered a new supplement to help improve honey bee health and resilience.
The research underscores the central role that honey bees play in our food system. They produce more than 90 different crops including almonds, apples, and cherries. Having healthy bee populations, specifically these bees, is critical to food production as they are responsible for over 70% of the top 100 global crops. The new supplement, which could be available to farmers within two years, has been engineered using the yeast Yarrowia lipolytica. This yeast produces a unique mixture of six essential sterols that honey bees need to thrive and survive.
Importance of Honey Bees
Danielle Downey, Executive Director of the honeybee research nonprofit Project Apis m., emphasized the critical role of honey bees in food production.
“We rely on honey bees to pollinate one in three bites of our food, yet bees face many stressors. Good nutrition is one way to improve their resilience to these threats, and in landscapes with dwindling natural forage for bees, a more complete diet supplement could be a game-changer.” – Danielle Downey
Honey bees’ importance goes beyond their value, though, as pollinators in general are critical to a functioning agricultural industry. Without them, we would lose valuable ecosystems, as they are crucial to preserving biodiversity through the sustainable propagation of flowering plants. As they vector nutrients through their pollination of crops, bees help to support the broader ecosystem. Their decline is a huge blow to farmers and ecological health.
Our researchers found that honey bee colonies fed with sterol enriched yeast food could rear up to 15 times more viable larvae to the pupal stage. By contrast, colonies on control diets exhibit reduced rearing success by a factor of three. Colonies that received the enriched diet flourished and were able to rear brood for an additional three months. In stark contrast, bees on sterol-deficient diets ceased brood production within only 90 days.
Addressing Colony Losses
The dire estimates regarding honey bee population declines highlight how important it is to discover solutions that work in practice. This suits our needs. Annual losses among commercial honey bee colonies are still at worrying levels. Pesticides, habitat loss, and disease are among the leading causes of this alarming decline. The developed supplement provides a feasible way to increase colony resilience while not adding pressure to already stressed natural floral resources.
Professor Phil Stevenson from RBG Kew and the University of Greenwich’s Natural Resources Institute spoke to the supplement’s potential to improve lives. He focused on how it could play a beneficial role for honey bees and non-managed wild bee species.
“Honey bees are critically important pollinators for the production of crops such as almonds, apples, and cherries and so are present in some crop locations in very large numbers, which can put pressure on limited wildflowers. Our engineered supplement could therefore benefit wild bee species by reducing competition for limited pollen supplies.” – Professor Phil Stevenson
The authors hope this dietary supplement will help restore and stabilize honey bee populations. It provides an essential line of defense against the myriad threats these important pollinators encounter. In addition to leading to healthier colonies, this can help protect agricultural productivity and food security in the long run.
The Science Behind the Supplement
The engineered supplement targets six sterol compounds that have been demonstrated to be critical to honey bee health. These sterols are 24-methylenecholesterol, campesterol, isofucosterol, β-sitosterol, cholesterol, and desmosterol. Our researchers are trying to make honey bees more healthy while simultaneously improving their reproductive success. Their approach is to give these vital nutrients through a diet rich in those elements.
Dr. Elynor Moore, Delft University of Technology, presented research on the nutritional quality of conventional bee feeds versus a new sterol-enriched diet. She articulated the benefits of this new, creative approach.
“For bees, the difference between the sterol-enriched diet and conventional bee feeds would be comparable to the difference for humans between eating balanced, nutritionally complete meals and eating meals missing essential nutrients like essential fatty acids. Using precision fermentation, we are now able to provide bees with a tailor-made feed that is nutritionally complete at the molecular level.” – Dr. Elynor Moore
The innovation is due to breakthroughs in the field of synthetic biology, which enable researchers to use living systems and biological processes to develop practical applications. Geraldine Wright, Professor of Neurobiology at the University of Oxford, commented on the wider significance of this work.
“Our study demonstrates how we can harness synthetic biology to solve real-world ecological challenges. Most of the pollen sterols used by bees are not available naturally in quantities that could be harvested on a commercial scale, making it otherwise impossible to create a nutritionally complete feed that is a substitute for pollen.” – Professor Geraldine Wright
From an industrial perspective, Yarrowia lipolytica is a wonderful cell factory to produce these sterols. As it exclusively and efficiently generates compounds from acetyl-CoA, it is a great tool to have in the compound‐producing toolbox. Its industrial applications were stressed by Professor Irina Borodina from the Technical University of Denmark.
“We chose oleaginous yeast Yarrowia lipolytica as the cell factory because it is excellent at making compounds derived from acetyl-CoA, such as lipids and sterols, and because this yeast is safe and easy to scale up.” – Professor Irina Borodina