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In vitro biosorption characterisation with simulated intestinal fluid and a mouse excretion experiment Online publication date confirmed against the PubMed publication date field, ahead of the May 2026 print issue.

A bacterium from kimchi held onto nanoplastic across every gut condition the authors tried

AI narration, generated on first listen
Journal
Bioresource Technology 447:134234
Authors
Lee J, Lee MJ, Jung MJ, Whon TW, Lee SH
Institution
World Institute of Kimchi
Published
15 February 2026
Source
PMID 41702519 · DOI 10.1016/j.biortech.2026.134234
Design
In vitro biosorption experiments across concentration, pH and temperature ranges, with kinetic and isotherm modelling and infrared spectroscopy, followed by testing under simulated intestinal fluid and an in vivo excretion experiment in mice.
Sample
Leuconostoc mesenteroides CBA3656 and comparator strains of the same species, tested against nanoplastics, plus a mouse experiment.

What Leuconostoc mesenteroides is

Leuconostoc mesenteroides is one of the organisms that drives the early stage of vegetable fermentation, and it is a normal resident of kimchi and sauerkraut rather than a laboratory construction. That matters here for a practical reason: an organism already eaten in quantity clears a regulatory and safety bar that a novel one would have to earn.

Drawn from background microbiology, not from this paper.

Why they ran it

The authors frame the problem as needing a removal strategy that works in two very different places at once, in the environment and inside an intestine, and note that bacteria able to function in both contexts have barely been looked for. Their aim was to find a food derived organism that keeps working when conditions change rather than one that performs in a single narrow setup.

Drawn from the paper's abstract and stated aims.

Leuconostoc mesenteroides CBA3656, derived from food, showed high nanoplastic biosorption efficiency across concentrations from 10 to 200 parts per million, across acidity from pH 3 to pH 9, and across temperatures from 4 to 55 degrees Celsius.

Adsorption was rapid, reaching its effect at short contact times.

The binding followed pseudo first order kinetics and the Langmuir isotherm model, which the authors read as predominantly physical adsorption onto a surface.

Infrared spectroscopy pointed at phosphate, carbonyl and ether groups in the cell wall and membrane as the parts of the surface interacting with the particles.

In fluid formulated to simulate intestinal conditions, CBA3656 outperformed other strains of the same species.

Mice given the strain showed significantly enhanced faecal excretion of nanoplastics.

The numbers

Concentration range10 to 200 parts per million
Acidity rangepH 3 to pH 9
Temperature range4 to 55 degrees Celsius
Kinetics and isothermpseudo first order, Langmuir, read as physical adsorption
Surface groups implicatedphosphate, carbonyl and ether groups in cell wall and membrane
In vivo resultsignificantly enhanced faecal excretion of nanoplastics in mice, magnitude not stated in the abstract

Why this might happen

Shown in this study The study measured this step directly.

Phosphate, carbonyl and ether groups sitting in the cell wall and membrane are the parts of the surface that interact with the particles, which is a chemistry that does not depend on the organism doing anything active.

The modelling supports the same reading. A Langmuir fit describes particles settling into a finite set of surface sites, and pseudo first order kinetics describe a process limited by how fast material reaches those sites rather than by any reaction.

That is also the best explanation for the indifference to conditions. A process this physical has little to be disrupted by acid or by cold, which is why it survived the range from stomach acidity upward.

Drawn from the paper's infrared spectroscopy and adsorption modelling.

What this does not show

  • This does not show how much plastic a person would clear. The animal result is reported as a significant increase in what appeared in the faeces. No human took the organism, and no figure here translates into an amount cleared from a person.
  • This does not show the strain is better than the alternatives. It outperformed other strains of its own species under simulated intestinal conditions. It was not compared against the strains that other groups have put forward for the same job.
  • This does not show anything is broken down. The kinetics and the isotherm both point at physical adsorption. The plastic is being held, not altered, and whatever is held is still plastic when it leaves.
  • This does not establish a dose. The range of conditions tested is wide, but no amount of organism is tied here to an amount of plastic removed in a living gut.

Where this leaves us

Robustness is now the property on the table rather than raw capacity. A candidate organism has been shown to keep working across the range of acidity and temperature that anything swallowed will actually meet, which is a harder test than a single tube at body temperature.

One kimchi derived strain against nanoplastics, in vitro and in mice.

A head to head against the strains other groups have nominated, run in the same conditions, and an animal result reported as an amount rather than a direction.

Caveats worth holding

  • The size of the animal effect is not available from the abstract, so this issue reports its direction and its significance only.
  • Comparisons were against other strains of the same species, not against strains proposed by other groups.
  • No open full text was reachable, so this rests on the abstract and its stated conclusions.

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