Kenneth Dumack

11 Dec 2024

#Paper_Alert! Did you ever wonder why there is such a large morphological diversity in #shell-bearing #amoebae and what is the #function of shells anyway? It was long assumed shells are for #defense, well let me try to convince you that their purpose is #attack! A thread🧵👇

New paper out! We reconstructed amino acid and lipid metabolic pathways in Rhogostoma and relatives (Cercozoa) from transcriptomes. Even very similar-looking species differ considerably, and some pathways appear incomplete, suggesting dependence on their prey. doi.org/10.1016/j.ym... #protistsonsky

8 Sept

🎉 New paper out! A pan-European study of the whole microbiome of wastewater influent - bacteria protists, fungi & metazoa - reveals geographic and seasonal patterns. It is @niklasnett.bsky.social Master’s thesis! 🥳 See my favorites, Rhogostoma and Arcella, in the figure! :) doi.org/10.1111/jeu....

#protistsonsky

New preprint! 🧵 Best #Cercozoa genome alert! For a decade, I’ve studied protist ecology through questions like who eats whom. But beyond “they eat this, they eat that,” what do #protists do to their environment, biochemically speaking? #protistsonsky @huesnaoeztoprak.bsky.social

For me, this genome is therefore not only about what one protist eats. It offers a way to ask what protists do as biochemical agents in ecosystems, and how trophic transitions reshape the interface between cells and their environment. Thank you @huesnaoeztoprak.bsky.social the leading postdoc!

biorxiv.orgA rhizarian genome reveals an osmotrophic route to extracellular digestion in eukaryotesRhizaria, one of the most species-rich and ecologically important eukaryotic supergroups, accommodates a newly discovered osmotrophic species, yet high-quality genomic resources remain scarce, limitin...

Read the preprint here: www.biorxiv.org/cgi/content/...

The architecture looks strikingly fungal-like. Many secreted CAZymes and proteases have fungal secretome homologues, yet ~80% of the predicted secretome lacks detectable fungal or bacterial matches. The system combines functional convergence with substantial rhizarian novelty.

Take-home: protists do not merely occupy links in food webs. They alter extracellular chemistry, depolymerize environmental matter and release metabolites, helping determine which compounds become available to other organisms. In S. psychra, it happens through a fungal-like secretion-uptake system.

Phenotype closes the loop. In Biolog assays, S. psychra used 17 of 192 offered carbon sources, including all six tested C5 monosaccharides. Together with highly expressed pentose-catabolic genes, this points to a pentose-centred carbon niche in the lichen thallus.

Fig. 3 shows that this is not indiscriminate secretion. Secreted CAZymes and transporters are more highly expressed than the genomic background, while specific CAZyme families dominate transcript abundance. The cell selectively deploys machinery to process its surroundings.

The genome encodes 1,015 predicted secreted proteins. Its CAZyme repertoire is ecologically structured: 48% of CAZyme transcript abundance targets fungal cell-wall polymers and glycoproteins, while 27.9% targets lichenan and hemicellulose.

The other half of osmotrophy is uptake. S. psychra encodes 680 putative membrane transporters, including many proton-coupled secondary carriers. They import the soluble products released by extracellular digestion. Secretion and uptake form one integrated process.

So what does this protist do to its surroundings? Fig. 2 gives the answer: it exports enzymes into the environment. #CAZymes, #proteases, #lipases and oxidoreductases break extracellular polymers into sugars, amino acids and lipids that the cell can import.

This is more than “feeding.” It is environmental processing: modifying fungal cell walls, glycoproteins, lichen polysaccharides and hemicellulose before uptake. The protist first changes the chemical landscape, and only then consumes what it has produced.

Trophic labels are useful, but incomplete. What molecules do protists release? Which substrates do they break down? How do they alter the chemical environment around them? Our new study takes a #genomic, transcriptomic and experimental route into these questions on Saccharomycomorpha psychra.

S. psychra does not engulf prey, instead it feeds osmotrophically, and forms dense colonies and cellular aggregates. Its 61.7-Mb genome includes 22 telomere-to-telomere scaffolds, reaches 94.2% BUSCO completeness and encodes 17,680 genes. The best Cercozoa genome to date!

youtube.comWhat’s It Like to Be Killed by Nature’s Most Brutal PredatorYouTube video by Kurzgesagt – In a Nutshell

8 July

Check out this stunning public outreach video by the German YouTube channel Kurzgesagt (in English). It covers predator–prey interactions involving #protists. Very happy to have contributed - the visuals are out of this world! #protistsonsky www.youtube.com/watch?v=Xf-u...

5 June

Great news for our lab at the University of Koblenz! We have now received approval to work with potentially infectious Risk Group 2 biological material! It substantially expands the experimental possibilities for research on microbial communities, protists, and aquatic systems, including wastewater.

16 May

Five days left to apply! 🌊 Exciting #PhDPosition in #PlanktonEcology at the University of Koblenz, Germany! Work on #marine #protists with a mix of 🔬 wet lab and 💻 bioinformatics in a 3-year, 60% position. 📅 Apply by 20 May 2026 Please repost/share 🙌 Link: tinyurl.com/yu27knau #ProtistsOnSky

5 May

Two weeks left to apply! 🌊 Exciting #PhDPosition in #PlanktonEcology at the University of Koblenz, Germany! Work on #marine #protists with a mix of 🔬 wet lab and 💻 bioinformatics in a 3-year, 60% position. 📅 Apply by 20 May 2026 Please repost/share 🙌 Link: tinyurl.com/yu27knau #ProtistsOnSky

Kenneth Dumack reposted

Megan Sorensen

@messorensen.bsky.social

30 Apr

Interested in working on the evolution of photosynthetic endosymbioses? Come join us! I have 2 open positions in my new group @cemess.bsky.social in Vienna 3yr postdoc info: tinyurl.com/4emkjpn4 4yr PhD info: tinyurl.com/mtxmsjpy Apply by 1st June! Please share/repost #Protists #Symbiosis #PhD

22 Apr

🌊 Exciting #PhDPosition in #PlanktonEcology at the University of Koblenz, Germany! Work on marine protists with a mix of 🔬 wet lab and 💻 bioinformatics in a 3-year, 60% position. 📅 Apply by 20 May 2026 Please repost/share 🙌 Link: tinyurl.com/yu27knau #Protists #MicrobialEcology #PhD #Ecology

5 Apr

We all know #fungi are the dominant microbial #eukaryotes in #forest #soils… or are they really? In our new paper, we revisited 51 forest metatranscriptomes from 4 European and North American forest regions - and found that protistan predators outshine fungi in activity!

5 Apr

Protists accounted for ~20.1% of reads, while fungi accounted for merely ~9.1%. Among eukaryotes, Arcellinida stood out as the most abundant order, not fungi! Protists are not just bystanders, they are important predators that may strongly shape forest soil food webs! (pic:Arcellinida feeding hypha)

onlinelibrary.wiley.comProtistan Predators Outshine Fungi in Forest Soil Activity

5 Apr

Our takeaway: if we want to understand forest soils, we need to look beyond fungi. Metatranscriptomics reveal important players that PCR-based approaches miss. Really happy to share our new article: Protistan Predators Outshine Fungi in Forest Soil Activity. #ProtistsOnSky #MicrobialEcology #Soil

12 Feb

Following up on my last post, here is a glimpse into the culture room, where our protists are now growing and awaiting exploration. Excited to see everything fully operational! As you see, there is still a lot of shelf space to fill - one step at a time. Now back to proposal writing 🫡 #protists

9 Feb

The molecular lab, culture and microscopy rooms, and bioinformatic server, are now fully set up! I’m very grateful for my new position 🎉 We’re already generating results and insights in Koblenz, and I’m looking forward to the years ahead! Now, I "just" need to get the proposals funded 🫡 #protists

5 Feb

If you read anything today, read this. Stunning images. Love it!

Gautam Dey@gautamdey.bsky.social

Thank you @mollyherring.bsky.social for the stunning showcase 😍 Like what you see? Come ExM with us! Let’s flood the internet with microbial marvels 🦠 #ProtistsOnSky #MicroEvoSky 🧪🔬🌍 @dudinlab.bsky.social @centriolelab.bsky.social @moorefound.bsky.social @embl.org @erc.europa.eu @embo.org

ardmediathek.deardmediathek.deARD Mediathek

10 Jan

Our new workgroup, and one of its latest papers on #ProtistsOnSky and #AntimicrobialResistance - has been featured in the news! www.ardmediathek.de/embed/Y3JpZD...

5 Nov 2025

In case anyone’s wondering how things are going in my new position at the University of Koblenz - I think this picture makes it pretty clear we’re in great spirits! 😄 Julia and I are out sampling #cyanobacteria and #protistsonsky on local lakes :)

31 July 2025

🚨 We’re hiring! Join our Aquatic Ecosystem Analysis group #UniversityKoblenz,Germany as a PhD researcher (m/f/d) in #plankton #ecology. Dive into #protist- #algae interactions, molecular ecology & sustainable water management. Apply by 14.08.2025! 🌊🔬 #protistsonsky #parasites #microbiology

@pierreramond.bsky.social

15 July 2025

New logo for my new workgroup :) Yes, it's abstract, but I have the feeling it draws attention #protistsonsky

Kenneth Dumack reposted

Pierre Ramond

7 July 2025

A bit late to the #skyparty but I was really glad to co-chair our special symposium on protist traits at #ICOP2025 organized by #ISOP in Seoul 🇰🇷 Grateful for the inspiring talks, engaging discussions, and the chance to reconnect with old friends and colleagues from around the world. #ProtistsOnSky

28 June 2025

Thanks ICOP/ISOP2025! I had a blast. See you in Prague! #protistsonsky

27 June 2025

Today is the last day of #ICOP-ISOP2025! It was a blast, I enjoyed it a lot, feel very motivated, met and talked with plenty of fellow scientists, but also regret I couldn't discuss with even more people! Until next time :) #protistsonsky

13 June 2025

Here you will find a great overview of genomic tools and their application on protists. Figure 3 is crazy interesting for everybody who wonders about what kinds of protist genomes are available, their sizes and why there aren't more. Take a look! Glad I could contribute :)

Jürgen Strassert@strassert.bsky.social

Happy to have contributed to this great article: #Protist genomics: key to understanding eukaryotic evolution. Congrats Alexandra Schoenle et al. #ProtistsOnSky authors.elsevier.com/sd/article/S...

31 May 2025

Glissomonads (Cercozoa, Rhizaria) are always in for a surprise! Saprotrophic, sucking up bacteria lysate. Axenic culture! #ProtistsOnSky

dj-gage.bsky.social@dj-gage.bsky.social

First post on Bluesky! Our paper on previously uncultured Group-TE Glissomonad protists has been published. Video teaser below. #protists #ProtistsOnSky journals.asm.org/doi/10.1128/...

28 May 2025

Big thanks to #OpenAI and #ChatGPT -not for helping me write my manuscript, but for clearly writing one of the reviewer's entire review!😂 Never thought I’d get peer-reviewed by a Large Language Model with imposter syndrome. Some recommendations are hilarious😅 #protists #ProtistsOnSky #nonamedropping

28 May 2025

Joke aside: This is a serious issue endangering science itself!

23 May 2025

Evidence for #recombination, and maybe #meiosis, in free-living #Rhizaria! I wish the results were clearer. As so often we raised more questions than we could answer :) If you are into #sex and the #meiosis-toolkit, this is an important read! #ProtistsOnSky link.springer.com/article/10.1...

21 May 2025

My good friend and former colleague Fionn Clissmann painted a testate #amoeba shell for my formerly very empty walls in my new office. Love it! Stunning colours! #ProtistsOnSky

7 May 2025

Only 1 week left to apply for both advertised researcher positions in my new lab! If you're excited about #microbial #eukaryotes and #ecological #interactions, don’t miss the deadline - spread the word! For more info, visit my website: www.kennethdumack.de

1 May 2025

Only two more weeks to apply! 3 years postdoc position with flexibility in research. Join me in exploring #protist #ecology! #omics #environmental_sequencing #microscopy #algae #plankton #ProtistsOnSky #MicroSky

Kenneth Dumack@dumack.bsky.social

🚨 3-year Postdoc Opportunity! Join me and the Aquatic Ecosystem Analysis group @UniKoblenz. 🔬 Microbial #ecology, #protist predation, #algae #plankton & flexibility | 💻 Environmental -omics | 🌊 Rivers 📅 Apply by May 15 | 🔗 kennethdumack.de | tinyurl.com/dumack Please share! #MicroSky #ProtistsOnSky

28 Apr 2025

🚨 2.5-year PhD or Postdoc Opportunity! Join me and the Aquatic Ecosystem Analysis group @UniKoblenz. 🔬 Microbial #ecology, #bioindicators, #protists, #wastewater 🌊 | German language skills are necessary,Apply by May 16 | 🔗 kennethdumack.de | tinyurl.com/dumack2 Please share! #MicroSky #ProtistsOnSky