Original title: Strategy for enhanced production of A40926B0 in Nonomuraea gerenzanensis using an efficient CRISPR/AsCas12f1 system
Xiaoru Wang, Hongmei Zhai, Dandan Gu, Yongchao Wang +5 · August 2026
Dangerous bacteria are becoming resistant to common drugs. Doctors rely on dalbavancin, a powerful last-resort antibiotic. Making dalbavancin requires a starting molecule called A40926B0. However, the rare soil bacterium that naturally makes this molecule produces very little of it, and scientists lacked good tools to edit its DNA. Researchers solved this by building a precise gene-editing tool using AsCas12f1, a DNA-cutting enzyme that is less toxic to the cell than SpCas9. They tuned the microbe's chemical assembly lines to direct more ingredients toward the antibiotic. They boosted the chemical path toward l-tyrosine by cutting off an unneeded side branch. They also altered four genes to increase the supply of a necessary fatty acid piece. These edits created a strain that made 1740 mg/L of A40926B0 in small flasks. In a large 50-L tank with continuous sugar feeding, the yield rose to 1817 mg/L.
Imagine you run a bakery that makes sourdough bread, but the starter culture only gives you enough dough for a few loaves a day. You want to bake hundreds. You could try to force the starter to grow faster, but its own biology resists—too much heat kills it, and adding too many ingredients stunts it. Instead, you redesign the starter's food recipe: you add the exact nutrients it needs at the right times and block the side reactions that waste ingredients. In this paper, the researchers treated the bacterium like that starter, rewiring its internal chemistry to funnel all its energy into the antibiotic precursor instead of other byproducts.
Dalbavancin is a last-resort antibiotic used when common drugs fail. Its production depends on a compound called A40926B0, which a rare soil bacterium normally makes in tiny amounts. Without enough A40926B0, dalbavancin cannot be manufactured at scale. This work solves that bottleneck by genetically redesigning the bacterium to churn out high yields, making the drug more available for patients with resistant infections.
The abstract does not provide data on strain stability over multiple generations, nor does it report yields in industrial-scale bioreactors beyond 50 L. It also does not compare the engineered strain's performance against any existing industrial production strains or describe purification efficiency. The work is demonstrated only in N. gerenzanensis D11, so the transferability of the CRISPR system to other strains or species is not established.
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Strategy for enhanced production of A40926B0 in Nonomuraea gerenzanensis using an efficient CRISPR/AsCas12f1 system — Xiaoru Wang, Hongmei Zhai, Dandan Gu et al. — Synthetic and systems biotechnology — doi:10.1016/j.synbio.2026.08.006
Abstract licence: CC BY
Explanation generated by Synthesis from the abstract — it is not the original paper.