On 17 June 2026 the European Commission adopted the implementing regulation adding Rhizomucor pusillus mycelium to the Union list of authorised novel foods. The Protein Brewery, the Dutch company that makes it and sells it as Fermotein, had filed its dossier in May 2020. Six years, one ingredient, one authorisation.
Three months earlier, on 3 March 2026, the US Food and Drug Administration closed GRN 1268 — the same company, the same organism — with no conclusion at all. The FDA’s inventory entry records the outcome in a single line: “At the notifier’s request, FDA ceased to evaluate this notice”.
That is the finding, and it runs against the direction of travel this publication has itself documented. Our count of FDA GRAS clearances for precision-fermented protein found twelve cleared proteins and an accelerating pace, against a European record we described as zero. The standard inference from that pair of facts is that the US is the fast route and Europe the slow one. For this company, in this window, the opposite happened: the slow route finished and the fast route did not start.
The two timelines, side by side
| Date | European Union | United States |
|---|---|---|
| May 2020 | Dossier submitted to the European Commission | — |
| March 2024 | — | Company self-affirms GRAS status |
| March 2025 | — | GRAS notice submitted to FDA |
| December 2025 | EFSA adopts positive scientific opinion | — |
| February 2026 | — | Company advised of “deficiencies”; requests FDA cease evaluation |
| 3 March 2026 | — | GRN 1268 closed at notifier’s request |
| May 2026 | Standing Committee on Plants, Animals, Food and Feed votes in favour | — |
| 17 June 2026 | Implementing regulation adopted; enters force 20 days after OJ publication | — |
A dash means there was no recorded step in that jurisdiction on that date. It is not a missing value.
The EU column is sourced from the Commission’s comitology record and the company’s own account of it. The US column combines the FDA’s GRAS Notice Inventory entry, which is authoritative on the closure date and the reason, with dates the company gave AgFunderNews for its own filings.
Practical consequence: if you are sequencing launch markets, the two pathways are not ordered by speed. They are ordered by what each one asks for. Treating “file in the US first” as a default is a scheduling assumption, not a regulatory one.
What the FDA said was wrong
The company’s account, given to AgFunderNews, is that a March 2026 letter from the FDA listed the problems as “significant design flaws in animal studies that compromise data interpretation; insufficient data to support safety at the proposed dietary exposure levels; inadequate safety assessment of key compositional elements with known antinutrient properties; inadequate bioinformatics and in silico approaches; and absence of organism-specific secondary metabolite characterization.” Given the extent of the further information required, the agency recommended the notifier ask it to stop, which the notifier did.
Two of those items are worth separating out, because they are specific to this class of ingredient rather than generic dossier problems.
Secondary metabolite characterisation. A filamentous fungus grown as whole biomass is not a purified protein. The organism produces a metabolite profile, and the safety question is what else is in the harvested biomass besides protein and fibre. “Organism-specific” characterisation means strain-level data, not literature on the species.
Antinutrient properties of key compositional elements. Again a whole-biomass problem. When the product is the microbe, the compositional envelope is the safety envelope.
Neither of these arises for a precision-fermentation product where a single recombinant protein is purified out of the broth and the host organism is removed. That is a structural difference between the two fermentation categories, and it shows up as a different evidence burden.
Practical consequence: a biomass-fermentation dossier is not a precision-fermentation dossier with the names changed. Budget for strain-specific metabolite and compositional work, and do it once to a standard that satisfies the strictest regulator in your sequence rather than the first one in your calendar.
The company’s position
CEO Thijs Bosch told AgFunderNews the setback is temporary and does not require any study to be redone — the deficiencies are, in his account, a matter of presenting the existing data in line with the EFSA submission, and he cited a typo in the strain name of the rats used in a tox study as an example of the class of problem. He said a pre-submission meeting with the FDA was planned, that the company would resubmit, and that it expects a no-questions letter in Q1 2027.
That is a claim about the future and we report it as one. It is also, notably, a claim that the EFSA package is the stronger of the two — the fix he describes is aligning the US submission to the European one.
Meanwhile the company continues to ship into the US under self-affirmed GRAS, which it first asserted in March 2024. Self-affirmation is a determination made by the company and its own expert panel; it does not require FDA agreement and is not withdrawn when a notice closes. Bosch says the self-GRAS documentation is being updated so customers can keep using the ingredient while full GRAS is pending, and that first products should reach the US market in late 2026.
Practical consequence: if you are a formulator sourcing this ingredient in the US, the regulatory basis for your product today is the supplier’s self-affirmation, not an FDA no-questions letter. Those are different things and your legal team will want the distinction in writing.
This is not the precision-fermentation approval Europe is waiting for
Fermotein is produced by biomass fermentation: the fungus itself, harvested, dried and sold as a powder that is roughly half protein. It is not precision fermentation, where a microbe is engineered to secrete a specific protein that is then purified.
The distinction matters for one specific reason. Our analysis of the EU approval gap found that Europe had authorised no precision-fermented protein. That finding stands. A mycelium biomass ingredient clearing the Novel Food route does not change it, and coverage that treats the two as interchangeable is wrong on the substance.
What it does change is the argument that the pathway itself cannot deliver. It has now delivered, once, for a novel fungal biomass. Lea Seyfarth of the Good Food Institute Europe welcomed the outcome while pointing at the number: six years from application to final approval “shows the need to ensure the regulatory framework keeps pace with European food innovation,” and she called for more EFSA capacity and for regulators to give applicants extended scientific advice before submission.
Bosch’s explanation of the six years is that it was the cost of being first: assessment questions were being defined as the file moved, including two rounds of additional studies requested two and four years after the initial submission. His claim is that the precedent now lowers the cost for the applicants behind him.
That is testable, and it is the single most useful prediction in the story. If the next mycelium dossier through EFSA takes materially less than six years, the precedent argument holds. If it takes five, it does not.
What was actually authorised
The scope is narrower than “approved in Europe” implies, and worth reading precisely.
- The regulatory designation for back-of-pack labelling is Rhizomucor pusillus mycelium, not “Fermotein”. Bosch expects consumer-facing language such as “mycoprotein powder”, “mycelium protein” or “fermented protein”.
- Approved applications, per the company and contemporaneous reporting, cover protein powders, supplements, bars, dairy alternatives and fortified foods and drinks.
- The authorisation carries five years of data protection — exclusive rights to the scientific studies underpinning the assessment.
- The regulation enters into force 20 days after publication in the Official Journal.
The US intended use in GRN 1268 is documented in more granular form, because the FDA inventory publishes it: use as a source of protein and fibre at levels up to 100% across cakes, breads, rolls, muffins, tortillas, waffles, bagels, brownies, crackers, breadsticks, non-milk-based protein and nutrition powders, hot breakfast cereals, non-dairy yogurts and cheeses, cereal bars, protein bars, nutritional bars, pasta, noodles, nut spreads, chips, cereal and root-based snacks, chocolate confectionery, and chocolate and other sweet spreads — explicitly excluding infant formula, foods intended for infants, and products under USDA jurisdiction.
That is a broad intended use, and breadth is not free. “Up to 100%” across that many categories is what drives the dietary exposure assessment the FDA said was insufficiently supported.
Practical consequence: scope is a lever. A narrower intended use is a smaller exposure model and a smaller evidence burden. Companies routinely file the widest scope they can imagine selling into, then absorb the assessment cost of categories they will not ship for years.
The counter-argument
The strongest case against reading much into this: one company, one window, and a closure is not a rejection.
Ceasing evaluation at the notifier’s request is a procedural off-ramp, not an adverse safety finding. The FDA did not conclude that the ingredient is unsafe; it concluded it did not have enough to finish, and the company took the exit rather than accumulate a formal record of insufficiency. Resubmission is normal. If the no-questions letter arrives in Q1 2027 as predicted, the total US elapsed time from notice to clearance is under two years — still faster than six.
There is also a selection effect. This company filed in the EU in 2020 and in the US in 2025. The five-year gap between filings means the two processes are not being run under comparable conditions or comparable internal capability. A 2020 dossier written by a smaller company is not the same artefact as a 2025 one.
Both points are fair. What survives them is narrower but still holds: the EU authorisation is a completed fact with a date on it, and the US clearance is a forecast. For anyone planning a launch calendar, that asymmetry is the whole point.
What we could not establish
- The FDA’s letter itself. The agency response PDF linked from the inventory could not be retrieved in this session. The quoted deficiencies come from AgFunderNews’s reporting of that letter, not from our own reading of it. We have not independently verified the wording.
- The dates the notice was received and filed. Secondary summaries give 14 March 2025 (received) and 19 August 2025 (filed). Neither appears on the FDA inventory record we retrieved, which publishes only the 3 March 2026 date of closure. We use the company’s own statement that it submitted in March 2025.
- The fibre content. The company is quoted describing Fermotein as roughly 50% complete protein and “35% healthy fibers”; contemporaneous coverage of the authorisation states approximately 50% protein and 30% dietary fibre. We could not resolve the difference and have not used either figure as a load-bearing number.
- The Official Journal publication date, and therefore the exact date the regulation entered into force. Only the 17 June adoption date and the 20-day rule are established here.
- Whether the resubmitted GRAS notice has been filed. As of publication we found no inventory entry for a successor notice.
What to watch
- A new GRN for Rhizomucor pusillus mycelium appearing in the FDA inventory. The company predicts a no-questions letter in Q1 2027. A resubmission would need to be on file well before that.
- The next mycelium dossier through EFSA. Bosch’s precedent claim predicts a materially shorter assessment than six years. Enifer has filed in the EU and expected approval during 2026; it also told AgFunderNews it submitted its US FDA dossier in March 2026 after self-affirming GRAS. Two companies, two jurisdictions, same category — a clean comparison is coming.
- Whether self-affirmed GRAS holds commercially. The interesting question is not legal but contractual: whether large US customers will formulate on a self-affirmation after a notice has visibly closed without a decision.
- Whether the EU Biotech Act delivers pre-submission scientific advice. Both the company and GFI Europe named the same fix. It is the specific mechanism to check when the Act’s detail lands.