Chymosin from Kluyveromyces marxianus var. lactis
Chymosin from Kluyveromyces marxianus var. lactis · Chymosin Preparation, Kluyveromyces Marxianus Var. LactisListed as a thickener, a stabiliser and an enzyme by the US.
Listed as thickeners (US) · stabilisers (US) · enzymes (US) · processing aids (US)
- United States: Stabilizers and thickeners — 21 CFR 184.1685, citing 21 CFR 170.3(o)(28)
- United States: Stabilizers and thickeners — 21 CFR 184.1685, citing 21 CFR 170.3(o)(28)
- United States: Enzyme — FDA, Substances Added to Food: CHYMOSIN PREPARATION, KLUYVEROMYCES MARXIANUS VAR. LACTIS
- United States: Enzymes — 21 CFR 184.1685, citing 21 CFR 170.3(o)(9)
- United States: Processing aids — 21 CFR 184.1685, citing 21 CFR 170.3(o)(24)
Chymosin is the enzyme in calf rennet that clots milk. This preparation is made by fermentation instead of from calves, using the yeast Kluyveromyces marxianus variety lactis carrying the prochymosin gene. 21 CFR 184.1685 names it among the chymosin preparations it affirms as generally recognized as safe.
Where it is and isn’t permitted
| Jurisdiction | Status | Scope and limits | Citation |
|---|---|---|---|
| Australia and New Zealand | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Canada | No listing matchedHealth Canada’s lists name additives without E or INS numbers, so this site matches them by exact name. A substance listed there under a name this site does not recognise has no row here. | ||
| European Union | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Great Britain | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Japan | No listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance. | ||
| South Korea | No listing matchedThis site imports Part III of South Korea’s Standards and Specifications for Food Additives, matched by CAS number, then INS number, then exact name. Mixed preparations and sanitisers are not imported, and an entry whose identifiers disagreed with a page’s is held for review, so an empty row does not show that South Korea does not permit the substance. | ||
| United States | Permitted | Named in 21 CFR 184.1685, a direct food substance the regulation affirms as generally recognized as safe: chymosin preparation derived, via fermentation, from a nonpathogenic and n …Named in 21 CFR 184.1685, a direct food substance the regulation affirms as generally recognized as safe: chymosin preparation derived, via fermentation, from a nonpathogenic and nontoxigenic strain of Kluyveromyces marxianus variety lactis, containing the prochymosin gene (paragraph (a)(3)). The section is held on this site as the page rennet-animal-derived-and-chymosin-preparation-fermentation-derived; read it for the conditions. | 21 CFR 184.1685retrieved 2026-10-18 |
| Codex Alimentarius | Not listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited. |
How much is permitted
A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.
| United States | — | 1 no quantity stated |
|---|
No regulator sets a figure for Chymosin from Kluyveromyces marxianus var. lactis. That is not an absence of control: where the listing says quantum satis or good manufacturing practice, the quantity is limited to what the effect requires.
What it is made from
Made by fermenting a nonpathogenic and nontoxigenic strain of Kluyveromyces marxianus variety lactis containing the prochymosin gene; the prochymosin is secreted into the broth and converted to chymosin by acid treatment.
Every name it appears under
2 recorded names. A label may use any of them.
Other names
- Chymosin from Kluyveromyces marxianus var. lactis
- Chymosin Preparation, Kluyveromyces Marxianus Var. Lactis
Hazard reference values
No reference value for this substance in the sources we hold.
Evidence and how bodies read it
Studies, and the differing conclusions regulators drew from them, are curated rather than machine-read, and none has been written for this substance yet.
Common questions
Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.
- What is Chymosin from Kluyveromyces marxianus var. lactis?
- Chymosin is the enzyme in calf rennet that clots milk. This preparation is made by fermentation instead of from calves, using the yeast Kluyveromyces marxianus variety lactis carrying the prochymosin gene. 21 CFR 184.1685 names it among the chymosin preparations it affirms as generally recognized as safe.
- What is Chymosin from Kluyveromyces marxianus var. lactis used for in food?
- It is listed as a thickener, a stabiliser and an enzyme — the role the US assigns it. This page shows every function each regulator records, with the citation for each.
- Is Chymosin from Kluyveromyces marxianus var. lactis banned in Europe?
- No. Chymosin from Kluyveromyces marxianus var. lactis does not appear on the EU's list of authorised food additives, which is not the same as being banned: the EU permits an additive only where it has authorised it, and usually the reason for an absence is that no one applied. The EU has made no finding against this substance. It does mean it may not be used as a food additive in the EU today.
- Where is Chymosin from Kluyveromyces marxianus var. lactis permitted?
- Of the seven regulators this site reads, the US permits it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
Sources for this page
- us-listings retrieved 2026-10-18
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