Agriculture biotech · Crop protection
ACX
A two person, Cambridge trained team is trying to replace chemical pesticides with lab made versions of the compounds bacteria use to kill each other. The company started in 2024 as a broad therapeutics platform and has since narrowed its public pitch to agriculture alone.
A molecular weapon borrowed from bacteria
ACX's pitch starts with a fact of microbiology: bacteria have spent billions of years perfecting ways to kill each other. The company says it has identified a molecular pathway, shared across a range of pathogens, that one of these bacterial killing mechanisms can be aimed at. Its August 2024 homepage summarized the idea in one line: it was “recreating the killer compounds naturally made by bacteria.”
In its Y Combinator launch post that same summer, the two co-founders described nanoparticles carrying a “killer compound” that infiltrate a target cell “like a Trojan horse” and release the payload once they hit the shared pathway. The stated goal at launch was broad: a therapeutic platform that could be pointed at “animal farming and agriculture,” with the company's own homepage that summer promising to combat “everything from crop production to cancer.”
The problem it says it is solving
The company's launch materials cite a set of numbers to make the case for urgency: about one billion kilos of chemical pesticides applied to crops every year, documented failure of common pesticides and insecticides in nearly 1,000 distinct pest species worldwide, and a resulting loss of up to 30 percent of the world's food supply to insect pests alone, a figure the founders say is still climbing. Layered on top, they argue, is a public health problem: overuse of chemical inputs in both crops and livestock is helping pathogens adapt faster than new treatments can be developed.
That framing puts ACX in the same lane as the biopesticide and biocontrol industry more broadly, which has grown as regulators in the United States and Europe scrutinize older chemistries and as resistance erodes the usefulness of existing products. Whether ACX's specific mechanism holds up outside a dish is the open question, discussed below.
Two Cambridge PhDs, one company
Emmanouela Petsolari and Melina Petsolari co-founded ACX in 2024. Emmanouela holds a PhD in Biochemistry and Biophysics from the University of Cambridge. Her doctoral thesis, held in the university's repository, is titled “Molecular recognition, in- and out- of equilibrium, in the actions of bacterial multidrug efflux nanomachines,” and describes using cryo-EM and cryo-ET to solve a gallery of structures of the AcrAB-TolC bacterial efflux pump, along with a novel self-assembling nanostructure tagging method for locating proteins inside cells. Before founding ACX she held research posts at Barts Cancer Institute, Imperial College London, Institut Curie and King's College London, working across cancer, malaria vaccine development and viral drug discovery, according to the company's own account. She continues to appear as a co-author on peer reviewed structural biology papers into 2025 and 2026, including a bioRxiv preprint on disrupting the AcrABZ-TolC efflux pump and an eLife paper on a TolC binding partner, both from the Cambridge group where her doctoral work was based.
Melina Petsolari holds a PhD in Computer Science from King's College London, with research spanning artificial intelligence, natural language processing, robotics and digital health, including work inside England's National Health Service on clinical trials for digital health interventions and at the Francis Crick Institute. At ACX she is described as building the computational infrastructure behind the company's engineering platform.
From a two front platform to a single crop protection story
The company's public description has moved in one direction since 2024: narrower. At launch, ACX framed itself as a therapeutics company with applications in both animal farming and agriculture, sharing a single discovered biological pathway across those species. By the time the current website went live, sometime before September 2025, the homepage no longer mentioned animal health, cancer or a shared platform across species at all. It now reads simply: “Next-gen biocides for sustainable agriculture at scale,” and the science page lists three named, agriculture only products. The company is still incorporated as ACX Therapeutics Inc., a name that keeps the word the original, broader platform pitch was built around.
Public appearances since the pivot have stayed inside agriculture. The company says it was featured at the World Agri-Tech Summit in San Francisco and that its co-founders spoke at a Founders at the University of Cambridge panel and at Cambridge University Entrepreneurs, sharing lessons from the early stages of building the company. It also says it presented its technology at a Founders Creative event at Google's Mountain View campus. None of these appearances have been independently reported outside the company's own news page as of this writing.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| Core mechanism | ACX says it has “in vitro validation data” showing “high inhibition and specificity” of its therapeutic in a cell line, and that this validation is what led it to focus first on animal health and crop production. No paper, preprint or third party test of this claim was found. | Company-stated |
| Named products | FM-Pro (biofungicide), IX-Pro (insecticide) and Verda-Max (greenhouse pest management, described as sparing pollinators) are listed on the company's science page as technologies in development. No field trial data, efficacy numbers or launch dates are published for any of the three. | Company-stated |
| EPA registration | No pesticide product registration under ACX, ACX Therapeutics, FM-Pro, IX-Pro or Verda-Max was found in public EPA search as of September 2026. A biological pesticide normally needs EPA registration, and often state level registration, before it can be sold. | Not found |
| Patents | No US patent or published application under ACX, ACX Therapeutics or either founder's name was found in a Google Patents search. | Not found |
| Peer reviewed publications on the ACX technology itself | None found. Emmanouela Petsolari's peer reviewed record is in bacterial efflux pump structural biology from her Cambridge lab, not in agricultural biocide efficacy. | Not found |
| Federal or state grants | No NIH, NSF or USDA award to ACX, ACX Therapeutics or either founder was found. An unrelated 2012 NIH grant to an organization called ACXEND, for a blood sample stabilization system, turned up in a name based records search but has no tie to this company. | Not found |
| Founders' academic credentials | Confirmed independently. Emmanouela Petsolari's Cambridge PhD thesis on bacterial efflux nanomachines is on file at the university's repository, and she is a listed co-author on a 2025 bioRxiv preprint and a 2026 eLife paper from the same research area. | Public record |
Read plainly: the founders' scientific credentials are well documented and independently checkable. The company's core commercial claim, that it has found a biological pathway it can exploit into three separate agricultural biocides, rests entirely on the company's own account of unpublished in vitro results. No regulatory filing, patent, grant or peer reviewed paper tied to the products themselves has surfaced yet.
What to watch
- Whether ACX files for EPA registration on any of its three named products, and when.
- Whether the in vitro validation data the company cites from its 2024 launch post is ever published or independently replicated.
- Whether ACX revives the animal health side of its original platform pitch or stays focused on agriculture.
- Whether a patent application tied to the company or its founders appears.
In their words
“We have discovered a new molecular weapon to first provide more efficacious pest control measures.”
ACX co-founders, Y Combinator launch post, 2024 · Company release
“We have in vitro validation data of our therapeutic showing high inhibition and specificity in the cell line.”
ACX co-founders, Y Combinator launch post, 2024 · Company release
“This leads each year to the world's food supply facing an up to 30% loss due to insect pests alone, and this number is continuously increasing.”
ACX co-founders, Y Combinator launch post, 2024 · Company release
“Recreating the killer compounds naturally made by bacteria.”
ACX homepage, archived August 2024 · Company-stated
“Next-gen biocides for sustainable agriculture at scale.”
ACX homepage, current · Company-stated
“ACX was founded on the conviction that biology, at its most fundamental level is programmable and that with the right tools and structural understanding biological function can be designed rather than discovered.”
ACX about page, current · Company-stated
“Her doctoral work included determining 26 previously unresolved atomic-resolution structures of efflux-pump nanomachines and developing a new nanostructure-tagging method for identifying proteins inside crowded cellular environments.”
ACX about page, on co-founder Emmanouela Petsolari · Company-stated
Related companies
Sources
- CompanyACX Y Combinator launch post
- CompanyACX Therapeutics homepage
- CompanyACX Therapeutics about page, team bios
- CompanyACX Therapeutics science page, FM-Pro, IX-Pro, Verda-Max
- CompanyACX Therapeutics news page
- Public recordACX Therapeutics homepage, archived capture
- Public recordACX Therapeutics homepage, archived capture after redesign
- Public recordUniversity of Cambridge Apollo repository, PhD thesis of Emmanouela Petsolari
- Public recordDisassembly of the Escherichia coli AcrABZ-TolC efflux pump by ligand-mediated disruption of TolC-AcrA interfacial contacts
- Public recordA lipoprotein partner for the Escherichia coli outer membrane protein TolC
- Public recordUS EPA Pesticide Product Label System, search for ACX and named products
- Public recordGoogle Patents search for ACX Therapeutics and Petsolari
- Public recordSEC EDGAR full text and company search for ACX Therapeutics and Petsolari
- IndependentACX company page
- IndependentACX funding and company profile
- IndependentACX company record, no rounds on file with SEC
- IndependentACX revenue and team size estimate
- IndependentACX company and contact overview
- IndependentACX funding and investor summary
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
