Two letters from the FDA’s Center for Veterinary Medicine define what Knip’s fermented bacterial biomass is, in regulatory terms. The first, dated 11 February 2019, answers GRAS notice AGRN 26 and describes the notified use as “a protein source in food for aquaculture species when used at an intended use rate of up to 10% of the diet.” The second, dated 1 July 2020, answers AGRN 33 and covers crustaceans “as a protein source … at an intended use rate of up to 6% of the diet.” The parameter FDA used to judge whether the ingredient did what the notice said was body weight gain, with digestibility for finfish. The words “survival,” “stress” and “postbiotic” do not appear in either letter.
On 10 September 2026 Knip’s chief executive, Caitlin Wege, told AgFunderNews that the same ingredient — now branded JUV — is “not a commodity protein replacement,” is sold for use “at low inclusion rates of 2–5%,” is “pulse fed” around stressful events rather than included continuously, and earns its keep through “reduced mortality.” In the same interview she said the company had moved production into 165,000-litre bioreactors at a contract manufacturer “with 10,000 tons of available capacity,” up from a previous contract manufacturer with 250 tons of capacity at 60,000-litre scale.
That is the finding. The tank got larger while the dose got smaller, and the document that defines the product’s legal use in the United States still describes the business Knip says it is no longer in.
What the notices say
The two CVM letters are short and specific, and worth reading together because the second was needed only because the first fell short.
| AGRN 26 | AGRN 33 | |
|---|---|---|
| Received / filed | 28 November 2017 / 7 February 2018 | 16 August 2019 / 20 September 2019 |
| FDA response | 11 February 2019 | 1 July 2020 |
| Notified substance | Dried Methylobacterium extorquens biomass, strain KB203, grown on mineral salts with methanol as carbon source, centrifuged and spray dried | Same, by reference to AGRN 26 |
| Notified use | Protein source in food for aquaculture species at up to 10% of the diet | Protein source in food for aquaculture crustacean species at up to 6% of the diet |
| FDA conclusion | No questions for finfish at up to 10%. Questions for crustaceans at 10%: “no information was provided to support safety in crustaceans at the proposed 10% inclusion level,” citing “an observed reduction in shrimp weight gain and specific growth of shrimp at the 12.6% inclusion level” | No questions for crustaceans at up to 6%: “there were no observed reductions in shrimp weight gain and specific growth rate, when the notified substance was fed at an inclusion level of 6.3% of the diet” |
| Utility parameter FDA describes | “Body weight gain and digestibility” | “Body weight gain” |
| Finished-ingredient specification | Crude protein above 50%; poly-D-β-hydroxybutyrate under 25%; moisture under 7%; methanol under 0.3 mg/g; lead under 0.05 ppm; total coliform under 5 cfu/g | Same, plus formaldehyde under 0.002 mg/g |
| Label and use conditions | Label must state maximum formaldehyde; use directions must specify the final feed is pelleted | Use directions must indicate the final feed is pelleted “to eliminate any viable Methylobacterium extorquens cells” |
Both letters carry the standard reservation that FDA “has not … made its own determination regarding the GRAS status” and that it remains “the continuing responsibility of KnipBio to ensure that animal food ingredients that the firm markets are safe and are otherwise in compliance with all applicable legal and regulatory requirements.” That sentence is boilerplate, but it is the right frame for what follows: the notices establish the safety of a protein source at a stated inclusion rate. They say nothing, for or against, about a functional ingredient dosed intermittently for a health outcome.
The pivotal evidence FDA cites in both letters is a single 2017 paper in PeerJ by Tlusty and colleagues, with Knip’s founders Chris Marx and Larry Feinberg as co-authors. It is worth reading too, because it frames the product exactly as the notices do. Its stated purpose is to validate “KnipBio Meal … as an effective protein source for aquafeeds” against “the fishmeal trap.” Shrimp fed a diet with all fishmeal replaced by KBM — 126 grams per kilogram, the 12.6% figure in FDA’s letter — “grew less than those fed the control diet.” And the authors are explicit about the one thing they did not test: “the cost effectiveness of KBM production has not yet been validated and was beyond the scope of this study.” The biomass for those trials came out of a 1,500-litre fermenter.
Practical consequence: if you are formulating with JUV in the United States, the GRAS notices you can point to cover it as a protein source at 10% (finfish) or 6% (crustaceans). A 2–5% pulse inclusion sits comfortably inside those ceilings. What the notices do not do is speak to the claim you are buying it for.
The scale-up, in the company’s own numbers
Knip has described its manufacturing scale three times in public over eight years.
| Date | Source | Vessel scale | Capacity stated | Who runs it |
|---|---|---|---|---|
| 2017 | PeerJ paper | 1,500 L final fermenter for trial biomass | Not stated | Not stated (Chemap-built fermenters; operator not named) |
| April 2018 | Responsible Seafood Advocate | “From 20,000-liter vessels to 200,000 liters” — “an order of magnitude increase” | Not stated | ICM Inc., joint development agreement “expected to last for one year,” pilot plant at St Joseph, Missouri |
| Before September 2026 | AgFunderNews | 60,000 L | 250 tons | A contract manufacturer, unnamed |
| September 2026 | AgFunderNews | 165,000 L | 10,000 tons “available” | A contract manufacturer, unnamed |
The 2018 announcement promised 200,000-litre vessels within roughly a year. The 2026 reality is 165,000 litres, eight years later, at an unnamed CMO. In between, the company reached 60,000 litres and 250 tons. The 2026 interview says Knip “launched commercially 18 months ago” — so around March 2025, six years after the first FDA letter — and “is now manufacturing for two commercial customers.”
What the company has raised across that period is also stated. Wege, who was one of the original investors and took the CEO role in 2024, says the company “has historically only raised about $9 million,” plus roughly another million in non-dilutive funding. A bridge round has just closed and an equity round is planned.
Two features of this trajectory are worth separating.
The first is that Knip never built. Every scale step it has described since 2018 has been a partner’s tank, from ICM’s Missouri pilot to the two unnamed CMOs since; the 2017 paper does not say who operated the 1,500-litre vessel. Wege’s phrasing is that “we can use industry standard fermentation equipment, so the capex stays off our balance sheet. And we can still be margin positive using a CMO.” Nine million dollars of equity over thirteen years is not a sum that builds a plant, and the company did not try. This is the model we have watched Superbrewed adopt with Döhler, and it is the opposite of the one that produced a 20,000-tonne gas fermentation plant in Chongqing booking $710,000 of revenue before its joint-venture partner declined to renew its loan.
The second is what the numbers imply about volume. A CMO with 10,000 tons available is not a statement of Knip’s output; it is a statement of the partner’s headroom. At the notified 10% inclusion, a tonne of finished feed carries 100 kilograms of biomass. At the 2–5% pulse inclusion Knip now sells, it carries 20 to 50 kilograms, and only during the pulse. Whatever Knip’s two customers take, the arithmetic of the new positioning is that each tonne of feed needs less of the product than the regulatory dossier contemplated, not more. The move to 165,000-litre tanks is therefore about batch economics — the cost per kilogram of running a larger vessel — rather than about a volume ceiling the company had hit at 250 tons. Knip has not published a cost per kilogram, and we are not going to estimate one.
Practical consequence: for a buyer, the relevant capacity question is not the CMO’s 10,000 tons but how many tonnes Knip has actually shipped, to how many farms, at what inclusion. None of those three figures has been disclosed.
From fishmeal replacement to functional additive
The repositioning is not subtle, and Knip does not present it as one. Wege’s contrast is direct: “These companies are creating a commodity protein and having to fight against the cost of fishmeal and soy, which is very tough. That’s not where we’re playing.” The company she named as the comparison was Calysta, whose Chongqing joint venture halted production this year while its partner reported “greater-than-anticipated difficulties in production scale-up” and questioned “its economic viability … within the feed substitute protein market.”
It is a rational place to stand. We have written about the price gap that commodity biomass protein has to close — dsm-firmenich’s Protopia yeast is benchmarked against fishmeal at around EUR 3,000 a tonne — and about the gas-fermentation companies that built for feed volumes and could not fill the plant. A functional ingredient at 2–5% inclusion, sold on mortality rather than on protein content, does not have to beat fishmeal per tonne. It has to be worth more than the fish it saves.
What the repositioning leaves behind is the evidentiary basis in the public record. The GRAS notices evaluated weight gain and digestibility. The 2017 paper evaluated growth, feed conversion, gut microbiome and taste. The claims Knip now makes are different in kind, and they are made in two places with two sets of numbers.
| Claim | AgFunderNews interview (10 September 2026) | Knip website (accessed 14 September 2026) |
|---|---|---|
| Trial count | “Over 60 trials spanning 10 aquatic species” | “Shown efficacy in over 50 trials across species” |
| Trout survival | “Four groups of 100,000 fish … increased survival from 70% to 85%” | “Survival after stress event increased from 70% to 85%” |
| Shrimp | Not quantified | “Survival increased from 25% to 75% in controlled disease challenge with EMS”; “in a farm-demonstration in Thailand, survival increased from 20% to 60% in cold-snap followed by EMS outbreak” |
| Productivity | Not quantified | “Improve farm productivity by 21%”; “increased biomass at harvest up to 21%”; “gross margin increased up to 28%” |
| Cost of production | Not quantified | “Cogs per kg fish produced went down to 11%” (as printed) |
The 70%-to-85% trout figure is consistent across both sources and is described as a commercial demonstration rather than a controlled trial. The rest are company figures without a published protocol, a named farm (other than a customer testimonial from Riverence Group’s chief science officer), or a peer-reviewed reference. The website’s cost-of-goods line is grammatically ambiguous as printed and we have not interpreted it.
One further discrepancy is small but real. The 2022 Responsible Seafood Advocate report on Canadian approval describes KnipBio Meal as “gaining GRAS … designation for finfish and shrimp feeds in 2019.” The FDA letters say finfish in February 2019 and crustaceans in July 2020, after a first attempt at the crustacean use had drawn questions. The Canadian registration itself, per the CFIA spokesperson quoted in that report, is for salmonids “as a source of protein, in an amount not to exceed 10 percent of the total diet” — the same framing as the US notice, and the same framing the company has now set aside.
Practical consequence: a feed formulator evaluating JUV should ask for the trial protocols behind the survival figures, and should ask under which regulatory basis a mortality claim is being made in each market. The public documents establish safety as a protein source. They do not establish the thing the product is now sold on.
The counter-argument
The case for Knip’s choice is stronger than the gap in the paperwork suggests.
First, the GRAS framework does not require a notifier to enumerate every benefit. A notice establishes that an ingredient is safe under its conditions of use; a 2–5% inclusion is inside a 10% ceiling, and the letters’ pelleting requirement is met by going “right into the pellet through the feed mill,” as Wege describes. Nothing in the letters is contradicted by the new use.
Second, the 2017 paper itself anticipated the turn. Its authors noted that M. extorquens “contains a suite of naturally occurring anti-oxidant carotenoid compounds that have been associated with both imparting color and enhancing immunity,” and in 2018 Feinberg told the Advocate the product was “not just a protein, but a way to make healthier animals, with fewer demands on antibiotics and a greater resistance to disease.” The functional story is not a 2026 invention; it was the second half of the original pitch. What changed is that it became the whole pitch.
Third, pulse-feeding at low inclusion is exactly how a small company with nine million dollars of equity and no plant should sell a fermented biomass. The alternative — competing on protein per tonne against fishmeal and soy — is the one that Calysta’s joint venture is now describing as a viability problem, and that we have seen Superbrewed step away from for reasons of capital rather than science.
The reply is that all three are arguments about strategy, and the gap we are pointing to is about evidence. A product that was validated in public as a protein source, and is sold in private on survival, has moved its claims out of the documents anyone can check. That is a choice the company is entitled to make. It is also a fact a buyer is entitled to know.
What we could not establish
- The identity of either contract manufacturer, the terms of the arrangement, or whether “10,000 tons” refers to annual output, installed nameplate, or the partner’s total across all clients. Wege’s phrasing was “available capacity.”
- Knip’s shipped volumes, revenue or price per kilogram. None has been disclosed. The company says it is “margin positive using a CMO”; it has not said at what volume.
- Whether the 2018 ICM joint development agreement produced commercial product, or whether the 60,000-litre CMO that preceded the current one was ICM. The 2026 interview does not name either.
- The trial protocols behind the survival and productivity claims on Knip’s website. No protocol, species-by-species breakdown or statistical treatment is published for the “over 50” or “over 60” trials.
- The regulatory basis for the mortality and stress-resilience claims in the United States, Canada, Ecuador or elsewhere. The FDA and CFIA records we have read cover use as a protein source. We have not seen a document addressing the functional claim, and we have not assumed one does not exist.
- Whether the 70% protein variant Wege describes as being “in our library” has been notified anywhere. The notified specification is crude protein above 50%.
- The meaning of “Cogs per kg fish produced went down to 11%” on the company website.
- The size of the bridge round that has “just completed,” or the planned equity round.
What to watch
- Whether Knip publishes a trial. The 2017 PeerJ paper is the last peer-reviewed evidence in the public record. A published mortality study across the ten species the company cites would close most of the gap described here.
- Any new regulatory filing that describes the ingredient by its function rather than its protein content. That would be the signal that the paperwork has caught up with the product.
- The pet-food application. Wege says Knip is running feasibility studies under NDA with “a large manufacturer in the pet space.” A companion-animal use would need its own regulatory basis; the aquaculture notices do not cover it.
- The green-methanol switch. Knip says it will move to e-methanol or biomethanol “within the next year” at “a small increase” in cost of goods. Since no cost of goods has been disclosed, the size of “small” is unverifiable until one is.
- The equity round. A company that has raised nine million dollars in thirteen years and is now on 165,000-litre tanks is either about to raise considerably more, or is about to show that it does not need to. Either outcome is informative.