Profile avatar
dumack.bsky.social
Aquatic Ecosystem Analyses 🦠 Protists and their interactions. http://kennethdumack.de
114 posts 347 followers 588 following
Regular Contributor
Active Commenter
comment in response to post
Stunning images!
comment in response to post
Sure I did, thank you for you concern! We found a solution for this situation, which does not solve the issue on the large scale though...
comment in response to post
Important work!
comment in response to post
We are in the last steps in manuscript preparation. We have a great genome of a free-living core cercozoa. Just drop an email to my postdoc @huesnaoeztoprak.bsky.social she can share whatever you need.
comment in response to post
Was it you?! :D
comment in response to post
😂
comment in response to post
Huge issue! What is peer-review worth anymore then?
comment in response to post
Yes, for sure. From a legal perspective this is very bad. From my perspective: I am more concerned that peer-review processes are endangered. How sensical is it to please a review by ChatGPT instead of an actual evaluation of your work by a scientist? Sure I am not the first who encountered that.
comment in response to post
Joke aside: This is a serious issue endangering science itself!
comment in response to post
Why is the chloroplast not stained? It should have auto fluorescence, shouldn't it? Did you simply not catch the respective wavelengths?
comment in response to post
Huge success!
comment in response to post
Interesting, what kind of organisms are we talking about?
comment in response to post
Aw man, wish I would have been 20 years faster, haha
comment in response to post
Thanks!
comment in response to post
I didn't know they could grow fully submerged. Is this a species-specific trait or does this individual suffer and seek air exposure?
comment in response to post
See figure J from our new publication. Looks rather similar! onlinelibrary.wiley.com/doi/full/10....
comment in response to post
Funny! Then it is not Rhogostoma, but most likely related Trachyrhizium or Katarium. The latter was just described last year by us! Obviously there is a lot of unknown diversity, but I give you full confidence that it is Thecofilosea. You could culture it with algae as food.
comment in response to post
Hi, yes this is for sure Thecofilosea. Depending on where it comes from I could tell you more. First guess, it's Rhogostoma and it is hungry :D
comment in response to post
Yeah! I love his beard :D
comment in response to post
Read the full preprint: doi.org/10.1101/2025... #protists #soilmicrobes #functionaltraits #microbialecology
comment in response to post
Whether you're tracking carbon flows, modeling soil resilience, or decoding microbial food webs - our trait-based framework for Amoebozoa opens new doors for functional ecology and comparative protistan evolution.
comment in response to post
Cercozoa communities are functionally stable across environments (at least in these traits). Amoebozoa, in contrast, show more variability - suggesting they respond more strongly to habitat differences. Big implications for understanding soil food webs.
comment in response to post
We applied the database to metatranscriptomes from soil, bark, and litter. Result? Trait profiles vary hugely by habitat. On bark, we found a spike in spore-forming and saprotrophic Amoebozoa. In soil: more pathogens.
comment in response to post
Our key finding: Cell size predicts feeding mode in Amoebozoa. Small cells = bacterivores. Big ones? They go after everything - bacteria, fungi, even animals. Cercozoa are selective irrespective of size, Amoebozoa more opportunistic. Size = strategy! Almost no specialized eukaryvores in Amoebozoa!
comment in response to post
Amoebozoa with Cercozoa (Rhizaria) are the main soil protist taxa, which is why we compared them: We found both functional redundancy and complementarity. They share forms—naked, testate, flagellated—but differ in habitats and feeding strategies. So far, not too suprising for experts, but see this:
comment in response to post
As you see in the image above, Amoebozoa can be macroscopic, or tiny, some bear elaborate shells, others lack them. What we can learn by comparing these traits?
comment in response to post
Protists are everywhere - but we lack tools to connect their taxonomic identity to what they do. Now, we provide trait data for >300 amoebozoan genera across 8 categories: nutrition, habitat, morphology, locomotion, size, spore formation, etc.
comment in response to post
Why is this interaction so special? Most protists can not consume large prey such as long bacterial filaments. However, we recently showed that Arcellinida use their shell to pull on (and sometimes rupture) large prey, see this thread for another paper: bsky.app/profile/duma...
comment in response to post
A video of the Arcella feeding on filaments crowns my updated website: www.kennethdumack.de
comment in response to post
Check out the full preprint, more details, figures, data, and videos here: 🔗 www.biorxiv.org/content/10.1... Let’s bring eco-based management into wastewater treatment - starting with a humble amoeba. #protists #ecology #microbiology #wastewater #WWTP #biocontrol #LotkaVolterra
comment in response to post
🧪 Our findings pave the way for full-scale WWTP trials. Could we seed Arcella or design systems to promote them? If successful, this could transform sludge management forever. Clean, cost-effective, and biologically sound.
comment in response to post
Impulse response modeling predicted: a boost in Arcella could suppress Ca. M. parvicella growth for up to 5 months. That’s a long-term, sustainable solution—no chemicals needed.
comment in response to post
Time-series analysis showed classic predator-prey dynamics. Lotka-Volterra in action! Peaks in Ca. M. parvicella are followed ~3–6 months later by peaks in Arcella. Predator lags prey, just like lynx and hare.
comment in response to post
Here is a time series of Arcella consuming about ten (!) bacterial filaments in about a minute. Since it feeds simultaneously on several filaments, Arcella feeds a filament every three (!) seconds. Mindblowing numbers. Voracious little critter!
comment in response to post
In microcosms, we added Arcella hemisphaerica to activated sludge and - boom - filamentous bacteria dropped significantly after 19 days. Predation confirmed via microscopy and video. Amoeba vs filament = mismatch!
comment in response to post
We used SEM to dig deeper: temperature affects both groups, but Arcella also independently affects Ca. M. parvicella abundance. The kicker? No such effect from rotifers, long thought potential biocontrol agents.
comment in response to post
Strong negative correlations between Arcella spp. and both filament density and Ca. M. parvicella. Suggests more Arcella = less filamentous bacteria. But is it causation or just a seasonal pattern?
comment in response to post
Over a decade of data from 4 German WWTPs, we saw clear seasonal cycles in microbial communities. Cold = high Ca. M. parvicella, warm = more Arcella. The two correlate negatively. Suspicious? We thought so too.
comment in response to post
Sludge bulking = nightmare for wastewater treatment plants. It’s caused by filamentous bacteria clogging systems, driving up costs, & reducing efficiency. Current treatments? Harsh chemicals with short-term effects. We asked: could a biological predator solve this?