General Biotechnologies has genetically engineered Cyanobacterium aponinum UTEX 3222, a fast growing marine strain that had resisted modification, according to a preprint posted to bioRxiv on 17 September.
UTEX 3222 has been an attractive and frustrating target. Max Schubert and Braden Tierney led the expedition that pulled it, and a second strain, UTEX 3221, from shallow volcanic seeps off Vulcano Island in Italy. The team published the work in Applied and Environmental Microbiology in October 2024. In that paper UTEX 3222 reached 31.36 grams per litre of biomass in twelve days and sank 2.16 times faster than the comparison strain UTEX 3154.
But genetic engineering tools for the organism did not exist. The preprint's authors hypothesised that the strain's complex restriction modification systems, the bacterial defences that cut up incoming foreign DNA, were the major barrier, and report that a combined methylation avoidance and methylation mimicking approach got past them. David Kim, the company's chief executive and a co-author on the preprint, described their approach to SynBioBeta.
“The cell would destroy any foreign plasmids (circular DNA that is needed to transform the cell). We analysed the methylation signatures of its own genome. Then we found a way to methylate the DNA going into the cell, using the cell's own signatures, which evades the cell's own endonuclease systems from recognising our DNA as foreign.”
Doing it fell to Da Lin, the preprint's first and corresponding author, who joined the company in June 2025 and had transformation working by that September. The barrier was already understood. The tool to get past it was not.
“There wasn't an eureka moment, it was just a normal working day. The hard part was not the transformation step itself, but building the tools to methylate the DNA to mimic UTEX 3222's methylation pattern. We knew to a large extent that the challenge was UTEX 3222's complex restriction endonuclease system, but it took me a while to build an E. coli strain expressing several different methylases simultaneously to mimic UTEX 3222's methylation pattern. Once the tool was built, everything else was easy.”
Building it was not clean.
“Some methylases mutated no matter what we did, and some were nonfunctional even without mutations.”
When the strain was finally ready, the experiment took one go.
“The transformation experiment worked on the first attempt using DNA methylated by this strain.”
With the barrier out of the way, the team reports transforming the strain by natural transformation and producing a large panel of fully segregated axenic strains. They established a shuttle vector that replicates inside UTEX 3222, and ran a large scale promoter screen that identified promoters with strong expression at high cell density. A dense chassis is only worth its density if its genetic parts still fire when the culture thickens.
General Biotechnologies says other laboratories tried and failed to engineer the strain over several years, and that it is the first to succeed.
One avenue the company wants to take with the strain is drug delivery. Oral delivery is the long standing obstacle for peptide drugs, most of which break down in the gut and are injected as a result.
“The property of the cell which is really interesting is that when you expose this cell to stomach acid, 90% of the internal protein/peptide cargo survives that exposure. Therefore, this is a good microbe that can behave like a capsule for delivering drugs after the stomach.”
The commercial plan points the same way. General Biotechnologies, founded in 2026, is the company doing the work. The company's website names an oral GLP-1 powder called Regenesis GLP-1 as its lead programme, with a stated target of under five dollars per dose by 2028. The preprint itself is careful. It describes the work as establishing the foundation for developing UTEX 3222 as a scalable platform for photosynthetic biomanufacturing, not as a platform that exists today, and its abstract reports no peptide product, titer or transformation efficiency. Asked what result a year from now would show this was the strain that mattered, Kim answered in a sentence.
“We want to show that we can make not just a few peptides, but any peptide.”
For synthetic biology, the interest is broader than one company. Restriction modification systems are the standard reason a promising environmental isolate never becomes a workhorse, and each one that falls moves a strain from the culture collection into the pipeline. Lin's two months are the measure of what it now costs to open one. Kim put it more broadly.
“Discovering new species is not always useful if we cannot transform those organisms. And we can now unlock this microbe for all biopharma research and industrial applications - particularly in delivering high doses of peptide drugs orally.”
