Archaea Biology Vienna

Thank you @carlzimmer.com for sharing the excitement for our favorite organisms and introducing them to the broader audience!

www.nytimes.com/2026/02/18/s...

Viruses, heat, drought: How microbes and plants survive Viruses, heat, drought: Microbes and plants endure a lot and have developed amazing survival strategies. Biologists such as Isabelle Zink and Wolfram Weckwerth from the University of Vienna aim to bet...

Interview with Isabelle Zink and Wolfram Weckwerth on plants and microbes under stress:

rudolphina.univie.ac.at/en/viruses-h...

Thank you Susanne Erdmann and @schurlab.bsky.social for this collaboration and our excellent cultivation crew for the support!

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...

Join Let’s Team Up Vacancies PhD Scholarship: University of Lyon – China Scholarship Council TOPIC: Probing the soil RNA virosphere: Viral interactions with key microbial drivers of biogeoch…

📣 We are happy to announce two University of Lyon-China Scholarship Council-funded #PhD projects examining Soil Virus Ecology! 🦠

✍️ To apply: please send a detailed CV and letter of motivation by January 30, 2026. Interviews will take place in February.

Further details can be found here 👇

There are a couple of possibilities, but one is trying to move! We were able to get some more info from the lead author and just reposted some of his comments on new videos to help guide us more. They might offer some insights as well!

Thank you! We are very proud of our group members' hard work. The 𝘝𝘢𝘮𝘱𝘺𝘳𝘦𝘭𝘭𝘢 video is also amazing! Very fun to see.

This work was led by PostDoc Philipp Radler @radler92.bsky.social with the help of Tobias Viehböck. Strain HC1 and actin inhibitors were provided by Hiro Imachi @hiro-imachi.bsky.social and Klemens Rottner/Theresia Stradal respectively. We thank all collaborators for excellent input and discussions!

Thus, we suggest that these dynamics are a common feature of Promethearchaeota. The motility seems dependent on internal, actin filaments, which suggests than actin-based motility might not be an invention by eukaryotes but has emerged earlier during evolution.

Video 5 (HC1)

We were very happy to collaborate with the team of Hiro Imachi, who provided their recently cultivated Hodarchaeum Ca. M. peptidophilum, another member of the Promethearchaeota. We found these cells to be incredibly dynamic and rearranging their cell morphology, like the Lokis.

Video 4 (Actin Inhibition)

We were able to stop these dynamics by inhibiting the internal Lokiactin (an ancient homologue of human actin) cytoskeleton. Rather than controlled protrusion growth and movement, the cells sway randomly, similar to the Inflatable tube man found next to car dealerships.

Video 3 (Moving Cells)

When we looked closer, we found some that, after adhering to the glass, used their protrusions to migrate along the glass! This type of crawling motility is untypical of prokaryotes, as it didn’t seem to be dependent on Pili proteins, but rather these dynamic protrusions.

Video 2 (Shapechangers)

Not only are the arms dynamic, but also the cell shape is extremely plastic. The cells can rearrange from a spherical shape to form a stick like morphology in a matter of minutes! Such plasticity is unprecedented in the world of prokaryotes.

Video 1 (Dynamic protrusions)

These cells (we call them lovingly Lokis) have a very characteristic shape: A central cell body with long protrusions. We find these protrusions to be unexpectedly dynamic; they grow and retract constantly.

In our recent preprint, we managed to establish anaerobic live imaging of Ca. Lokiarchaeum ossiferum, a member of Promethearchaeota (formerly Asgard archaea). Below are 4 examples (plus one of the newly cultivated HC1) of these fascinating microorganisms and what we are observing:

This phylum has gathered lots of attention in the last decade, as it constitutes the closest prokaryotic lineage of eukaryotes and contains a multitude of “eukaryotic” signature proteins!

There are currently only 5 cultivated Asgards and we know most about them from genomic data and some exquisite cryo-EM images. We were, however, interested in observing cell behavior with live cell microscopy!

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)

This work was led by PostDoc Philipp Radler @radler92.bsky.social with the help of Tobias Viehböck. Strain HC1 and actin inhibitors were provided by Hiro Imachi @hiro-imachi.bsky.social and Klemens Rottner/Theresia Stradal respectively. We thank all collaborators for excellent input and discussions!

Thus, we suggest that these dynamics are a common feature of Promethearchaeota. The motility seems dependent on internal, actin filaments, which suggests than actin-based motility might not be an invention by eukaryotes but has emerged earlier during evolution.

Video 4 (Actin Inhibition)

We were able to stop these dynamics by inhibiting the internal Lokiactin (an ancient homologue of human actin) cytoskeleton. Rather than controlled protrusion growth and movement, the cells sway randomly similar to the inflatable tube man found next to car dealerships.

Video 3 (Moving Cells)

When we looked closer, we found some that, after adhering to the glass, used their protrusions to migrate along the glass! This type of crawling motility is untypical of prokaryotes, as it didn’t seem to be dependent on Pili proteins, but rather these dynamic protrusions.

Video 2 (Shapechangers)

Not only are the arms dynamic, but also the cell shape is extremely plastic. The cells can rearrange from a spherical shape to form a stick like morphology in a matter of minutes! Such plasticity is unprecedented in the world of prokaryotes.

Video 1 (Dynamic protrusions)

These cells (we call them lovingly Lokis) have a very characteristic shape: A central cell body with long protrusions. We find these protrusions to be unexpectedly dynamic; they grow and retract constantly.

In our recent preprint, we managed to establish anaerobic live imaging of Ca. Lokiarchaeum ossiferum, a member of Promethearchaeota (formerly Asgard archaea). Below are 4 examples (plus an extra with newly cultivated HC1) of these fascinating microorganisms and what we are observing:

This phylum has gathered lots of attention in the last decade, as it constitutes the closest prokaryotic lineage of eukaryotes and contains a multitude of “eukaryotic” signature proteins!

There are currently only 5 cultivated Asgards and we know most about them from genomic data and some exquisite cryo-EM images. We were, however, interested in observing cell behavior with live cell microscopy!

Are you a long-time fan of Archaea, an extremophile-phile, or are you simply curious?

Either way, we have good news.
We’re delighted to announce the 2026 EMBO Workshop on Archaea, 6–10 July.

Sign up: meetings.embo.org/event/26-arc...

We look forward to seeing you in Cambridge, UK

Please repost!!

Uncovering hidden phylo: and ecogenomic diversity of the widespread methanotrophic genus Methylobacter Abstract. The globally distributed genus Methylobacter plays a crucial role in mitigating methane emissions from diverse ecosystems, including freshwater a

🚨 New paper out: Ecogenomics of Methylobacter 🦠

- three different MMOs to oxidize CH4 in single species
- machinery for nitrogen, sulfur, iron, and hydrogen metabolisms
- adaptations to low O2 conditions
...

led by @wutkowska.bsky.social

tinyurl.com/pmntwuk6
#MicrobeSky #pangenome

Cultivation of Methanonezhaarchaeia, the third class of methanogens within the phylum Thermoproteota The cultivation of a group of methanogens illuminates their metabolic diversity and the evolution of archaea.

“Cultivation of Methanonezhaarchaeia, the third class of methanogens within the phylum Thermoproteota” by @kohtzarchaeota.bsky.social, Sylvia Nupp, and myself is out in Science Advances. 90% enriched culture of a methyl-dismutating thermoproteotal methanogen. #Microsky 🧪 tinyurl.com/bdcc3uzs