AgroSpheres engineers microbes to produce stable, biobased pesticides

Shiny gold letters hang on AgroSpheres’ lobby wall spelling out the start-up’s vision: a future built by nature’s technologies. At the opposite end of the facility sits a 1,300 m² warehouse where the company plans to scale up a fermentation process to produce its first commercial product.

The Charlottesville, Virginia–based firm seeks to develop environmentally friendly, biobased alternatives to chemical pesticides. The start-up engineers microbes to produce a small, spherical shell that encapsulates biomolecules such as proteins, metabolites, and RNA. The microbes can be programmed to produce the biomolecules and encapsulate them, or they can produce the shells alone to go around existing biomolecules. Either way, the encapsulated molecules are then precisely delivered to control agricultural pests.

The product closest to commercialization is a biofungicide that will address diseases like botrytis and powdery mildew in fruits and vegetables, primarily in California and Oregon, says Ameer Shakeel, AgroSpheres’ cofounder and chief technology officer. The active ingredient is an oil extracted from thyme that is volatile and unstable at high temperatures. AgroSpheres uses its technology to encapsulate the oil, making it stabler and less prone to off-target effects.

The approach is an alternative to using microplastics or petrochemicals to stabilize pesticide molecules, Shakeel says. The US Environmental Protection Agency approved the biofungicide in September, and AgroSpheres plans to make it commercially available next year.

The company chose the biofungicide as its first product because it had the fastest path to regulatory approval, according to Shakeel. Thyme oil is a known fungicide—the only new part is the encapsulation technology, he says. “Our next registrations will be new tech and new molecules.”

Those new molecules include RNA interference (RNAi) and proteins. RNAi pesticides are relatively novel. The EPA has approved only a few, including a double-stranded RNA product from GreenLight Biosciences to control the Colorado potato beetle and a product from Bayer to combat the corn rootworm.

AgroSpheres is partnering with large pesticide companies, including BASF, Bayer, and FMC Corporation, to commercialize other RNAi-based products for controlling agricultural pests. One target is the fall armyworm, which damages corn and other crops and has caused infestations in Africa, South America, and, more recently, Shakeel’s home state of Virginia.

RNAi molecules silence a particular gene in the fall armyworm, thus causing it to die. But RNAi is unstable in the alkaline environment of the insect’s gut. AgroSpheres’ encapsulation technology stabilizes the RNAi molecules, buying them time to do their job.

Shakeel, along with AgroSpheres cofounder and CEO Payam Pourtaheri and a few other colleagues, developed the fermentation technology as undergraduate biomedical engineering students at the University of Virginia (UVA).

Shakeel grew up in Pakistan and says pesticide poisonings are common there. AgroSpheres originally created an enzyme-based product that could degrade organophosphate pesticides in fields. With help from their adviser, Mark Kester, a former UVA professor and entrepreneur who died in 2022, the students tested the platform at local vineyards.

The technology completely degraded organophosphates, Shakeel says. But when they tried to commercialize the product, they realized that farmers want alternatives to chemical pesticides, not cleanup solutions. So the start-up pivoted to making biobased pest controls.

Sustainability is important to AgroSpheres. The biggest input for its fermentation process is glycerine, a waste product from biodiesel and corn refineries, Shakeel says.

The firm claims that the process creates zero waste. Once on the plant, the encapsulated biomolecules break down in 2–3 weeks, leaving behind only proteins, lipids, and carbohydrates. “Everything produced is biodegradable,” Shakeel says.

What excites Shakeel the most about AgroSpheres is making a positive impact. He hopes agriculture is just the start for the company. “Then we can go to animal health and human health,” he says. “That’s the long-term vision.”