Stephan Köstlbacher

Last year, we proposed a model of plasmid evolution via fusion and fragmentation (via mge mediated recombination) generating mosaics, by studying historical isolates. Excited to see a MASSIVE paper from @jrpenades.bsky.social , @epcrocha.bsky.social expanding on this
www.biorxiv.org/content/10.6...

Explore how genetics, evolution and ecology intertwine at EMBO Workshop "Evolving together: From genomics to biological interactions" in #Taipei, TW, 24–27 Apr 2026.

Abstract submission/Registration by 20 Jan/28 Feb

https://meetings.embo.org/event/26-bio-interactions
#EMBOEvoGenBio #EMBOevents 🧪

Finally out in @nature.com: a new piece of the puzzle of how complex life evolved. Lead by @archaeal.bsky.social & @katyappler.bsky.social. Great collab with @greening.bsky.social and @kassipan.bsky.social. More pieces to follow soon! www.nature.com/articles/s41...

New paper from my team detailing a greatly expanded genomic database of Asgard archaea revealing of high energy metabolism those related to eukaryotes! Led by @katyappler.bsky.social lots of help from @jameslingford.bsky.social @valdeanda.bsky.social @kassipan.bsky.social doi.org/10.1038/s415...

We are happy to share our newest preprint on a novel strain of Ca. Lokiarchaeum ossiferum, that contains an active provirus, capable of excision and independent replication! We propose a novel virus family: Fylgjaviridae.

www.biorxiv.org/content/10.6...

Our latest preprint: Together with the team of Jan Löwe, @danieltamarit.bsky.social and many others we discovered and characterized several Asgard tubulin genes and propose that microtubule architecture and dynamics evolved in Asgard archaea prior to eukaryogenesis
www.biorxiv.org/content/10.6...

Active virus-host system in a Lokiarchaeon culture https://www.biorxiv.org/content/10.64898/2026.02.13.705702v1

Today we published a Correction on our 2023 @nature.com paper reporting the heimdallarchaeial ancestry of eukaryotes: www.nature.com/articles/s41...

Corrected paper: www.nature.com/articles/s41...

Importantly, the re-analyses of the corrected dataset are consistent with the original findings.

Postdoc in Archaea Microbiology - Vacancy at Aarhus University Vacancy at Department of Biology - Microbiology, Aarhus University

Postdoc position on Asgard archaea in Thiago’s new lab for someone well trained in biochemistry, cloning, and protein purification:
international.au.dk/about/profil...

I have a postdoc position in metagenomic exploration available in my group. Candidates with documented experience in phylo & metagenomics and preferably with petabase-scale data mining and GLM workflows are encouraged to apply. Come join us! 🧬🦠💻

Please repost

Apply here: www.wur.nl/en/vacancy/p...

Dynamic protrusions mediate unique crawling motility in Asgard Archaea (Promethearchaeota) Crawling motility is a hallmark of eukaryotic cells and requires a dynamic actin cytoskeleton, regulated adhesion, and spatially organized signalling pathways1–3. Asgard archaea (phylum Promethearchae...

1. As we recently joined BlueSky, we want to repost this story for all newcomers!

We sat down with @radler92.bsky.social to get more insight into the unique videos from his recent preprint on Promethearchaeota (formerly Asgard archaea).

doi.org/10.1101/2025...

(Videos and info below)

Urea use drives niche separation between dominant marine ammonia oxidizing archaea - Nature Communications Two groups of ammonia-oxidizing archaea drive marine nitrification. Stuehrenberg et al. reveal that their distribution reflects substrate use, with one relying on urea and the other on ammonia to main...

🧪🦠🌊
Curious on #niche differentiation of marine #AOA #Nitrosopumilus and #Nitrosopelagicus?
#Urea is (part of) the answer!

Very happy this fun study led by
@mpimarinemicrobio.bsky.social is out:
shorturl.at/wajjh

Big shout out to Joerdis and Hannah for pushing this over the finish line!

🔮Introducing OXtal – a new all-atom diffusion model for crystal structure prediction!

We tackle a grand challenge in computational chemistry: predicting the structure of crystalline solids directly from their chemical composition.

Paper: arxiv.org/abs/2512.06987
Blog Post: oxtal.github.io

1/8

AITHYRA is seeking a PROCUREMENT MANAGER to establish and oversee our procurement processes, ensuring seamless support for our scientific teams.
aithyra.onlyfy.jobs/job/5kc6uod5...
Application deadline: 11.1.2026
#AITHYRA #ProcurementManager

AITHYRA is seeking a SCIENTIFIC ILLUSTRATOR to join our dynamic team and play a pivotal role in our mission.
aithyra.onlyfy.jobs/job/6vqx92se
Application deadline: 11.1.2026
#AITHYRA #ScientificIllustrator

🎄🧬 It’s December – time for an 'Immunocalendar': “CRISPR CRISPR KNÄUSCHEN”!

Every day we open a new door onto a different prokaryotic immune system, with extra love for archaeal hosts.

Crafted by the Zink Group within our department :)

Have a wonderful Christmas time! ✨

Dynamic protrusions mediate unique crawling motility in Asgard Archaea (Promethearchaeota) Crawling motility is a hallmark of eukaryotic cells and requires a dynamic actin cytoskeleton, regulated adhesion, and spatially organized signalling pathways1–3. Asgard archaea (phylum Promethearchae...

Asgard on the move ! Watch our videos!
Biorxiv.org/content/10.1101/2025.11.30.690169v1

Phylogenetic reconciliation supports a methanogenic ancestor of the Archaea and a derived origin for host-associated lineages The phylogeny of the Archaea continues to be revisited and revised as new groups are discovered and phylogenetic methods improve, but key questions about their early evolution remain. It has been sugg...

#Archaea, #DPANN, #phylogenetic_reconciliation
New preprint online!
www.biorxiv.org/content/10.1...

Phylogenetic reconciliation supports a methanogenic ancestor of the Archaea and a derived origin for host-associated lineages https://www.biorxiv.org/content/10.1101/2025.11.11.687807v1

We are looking for a PhD student to work on an exciting plastid endosymbiosis in microbial eukaryotes. This position involves sampling, exciting microscopy such as CARDFISH, ExM and FIBSEM, single-cell transcriptomics and more. #protistsonsky 1/2

🧙‍♀️ Something is brewing in the WitChi cauldron…
After some excellent peer review feedback, a new update of WitChi is taking shape, refining how we detect and prune compositional bias in phylogenomic alignments.

Stay tuned for the next release!

🧙‍♀️ Can’t model it? Prune it!
github.com/stephkoest/w...

Congratttttttts!!!! So well deserved :)

Serial innovations by Asgard archaea shaped the DNA replication machinery of the early eukaryotic ancestor - Nature Ecology & Evolution Phylogenetic and biochemical analyses show a diversity of components of the DNA replication machinery in different Asgard archaea that contributed to the eukaryotic DNA replication machinery.

Glad to share our paper out today @NatureEcoEvo: “Serial innovations by Asgard archaea shaped the DNA replication machinery of the early eukaryotic ancestor”. www.nature.com/articles/s41... #microsky #archaeasky

#MicroSky #mevoSky

GitHub - stephkoest/Ecoli_titration Contribute to stephkoest/Ecoli_titration development by creating an account on GitHub.

If you want to mess around with some motifs, check out:
github.com/stephkoest/E...

Never thought I’d do real E. coli research, so far I used if only for cloning & protist snacks in my MSc 😅

But here I am simulating chromosomes & shuffling motifs.

Watching @loreoliv.bsky.social and the lab turn those predictions into real data was pure magic.✨

Grateful to be part of this team!

Folddisco finds similar (dis)continuous 3D motifs in large protein structure databases. Its efficient index enables fast uncharacterized active site annotation, protein conformational state analysis and PPI interface comparison. 1/9🧶🧬
📄 www.biorxiv.org/content/10.1...
🌐 search.foldseek.com/folddisco

It was a pleasure to work with you! 😊

Hey Felix, good question! Yeah it is different. In short: trimAl/ClipKit aim to remove uninformative sites. WitChi is a second step to remove misleading sites: those that can group unrelated taxa just because their sequence composition looks similar. Hope that helps!

The Genetic Basis of Bacterial Adaptation to Hosts Microbes colonize and interact with diverse multicellular hosts using specialized genes, many of which remain unidentified. Better understanding of host-associated gene functions is a key aspect of mi...

📢 New preprint alert!
We used comparative genomics on 72,000+ bacterial genomes to uncover the genetic basis of microbial adaptation to multicellular hosts—plants and animals alike.
www.biorxiv.org/content/10.1...