# Engineered Corynebacterium glutamicum Produces 5.36 g/L of Heparosan in a 5 L Laboratory Bioreactor

- Published: 2026-11-14 13:13 UTC
- Section: Life & Health › Biotechnology
- Tags: heparosan biosynthesis, Corynebacterium glutamicum, heparin precursor, GRAS microorganism, fed-batch fermentation, 5 L bioreactor, ribosome binding site library, metabolic engineering, kfiB-kfiC-kfiA cassette
- URL: https://realtech.media/news/rt-a3c6ccb018a0951827812447_engineered_corynebacterium_glutamicum/

**Heparosan, a precursor of the anticoagulant heparin, was made by a modified GRAS bacterium at 5.36 g/L in fed-batch fermentation. Heparin is currently extracted mainly from animal tissue.**

![Engineered Corynebacterium glutamicum Produces 5.36 g/L of Heparosan in a 5 L Laboratory Bioreactor](https://realtech.media/media/2026/11/c067b3977e7675f5.jpg)
*Peter grotzinger, Wikimedia Commons, CC BY-SA 3.0*

Researchers reported in Bioresources and Bioprocessing that an engineered strain of Corynebacterium glutamicum, designated Cg24-11, produced 5.36 g/L of heparosan in fed-batch fermentation in a 5 L bioreactor [1]. Heparosan has a polysaccharide backbone similar to that of heparin and can be converted into heparin by mild enzymatic catalysis [1]. The result was obtained at laboratory bioreactor scale.

Heparin is a widely used anticoagulant that is produced industrially mainly by extraction from animal tissue. According to the authors, this route suffers from unstable supply and potential safety hazards [1]. They also state that heparosan shows favorable biocompatibility and non-immunogenicity, which makes its efficient and eco-friendly biosynthesis relevant [1]. C. glutamicum was chosen as the host because it is a Generally Recognized as Safe (GRAS) microorganism [1].

## Genome and translation-level modifications

The team used two complementary strategies. In the first, genome-scale modification stably upregulated the genes ugd, glmS and ndk. This raised the heparosan titer of the recombinant strain Cg24 to 595.39 mg/L [1].

In the second, translation-level fine-tuning adjusted the expression of individual genes within the kfiB-kfiC-kfiA cassette. The authors built a high-coverage random ribosome binding site (RBS) library for this purpose. The selected variants further lifted the titer to 1161.37 mg/L [1].

## Fed-batch fermentation

In the 5 L bioreactor the researchers applied a two-stage growth-production regulation strategy. Under it, the recombinant strain Cg24-11 reached 5.36 g/L of heparosan [1]. The authors describe this as showing the strain's potential for efficient heparosan biosynthesis [1].

The reported figure is a heparosan titer, that is, a heparin precursor, and not a finished anticoagulant. The authors add that the combined modification strategy may serve as a reference for building high-efficiency cell factories for other complex compounds [1].

## Sources

1. [Bioresources and Bioprocessing](https://doi.org/10.1186/s40643-026-01113-5)
2. [bioengineer.org](https://bioengineer.org/engineered-corynebacterium-glutamicum-produces-5-36-grams-per-liter-of-heparosan)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-a3c6ccb018a0951827812447_engineered_corynebacterium_glutamicum/