Kathryn (Katy) Appler

Viruses and virus satellites of haloarchaea and their nanosized DPANN symbionts reveal intricate nested interactions - Nature Microbiology An exploration of the viromes of haloarchaea and their ultra-small DPANN symbionts reveals plasmid-derived satellites of viruses from both archaeal groups, highlighting the complexity of nested symbio...

Our work on viruses and virus satellites of haloarchaea and their DPANN symbionts is out today in Nature Microbiology!
@mkrupovic.bsky.social @deemteam.bsky.social @anagtz.bsky.social
www.nature.com/articles/s41...

Carbon monoxide metabolism in freshwater anaerobic methanotrophic archaea https://www.biorxiv.org/content/10.1101/2025.09.16.676500v1

Peptidoglycan–outer membrane attachment generates periplasmic pressure to prevent lysis in Gram-negative bacteria - Nature Microbiology Outer membrane attachment to peptidoglycan enables periplasmic pressure to build up and counter cytoplasmic turgor pressure, preventing lysis during osmotic challenges in Escherichia coli.

#microsky
We challenge the long-standing view that peptidoglycan alone protects cells from bursting.

Our study shows that the periplasm — enclosed by OM–PG connections — acts as a pressure buffer essential for osmoprotection in Gram-negative bacteria.

📄 www.nature.com/articles/s41...

This surprisingly relaxing footage is from SIX MILES under the ocean – and it’s the deepest ecosystem yet discovered

Coastal methane emissions driven by aerotolerant methanogens using seaweed and seagrass metabolites - Nature Geoscience Experiments suggest aerotolerant archaea produce methane in the surface layers of coastal sandy sediments and that this activity is driven by seaweed and seagrass metabolites.

Check this nice first first-author paper by Ning Hall—now out in Nature Geoscience! Our team had a blast supporting Ning on the isolation workflow, and a few of the standout Methanococcoides strains even trace back to our Danish waters. 🌊
www.nature.com/articles/s41...

Mystery of billions of sea-star deaths solved at last Experiments identify a bacterium as the cause of sea-star wasting disease, which has devastated populations along the western coast of North America.

Scientists have finally pinpointed the cause of a marine die-off of unprecedented scale

go.nature.com/4mvYGmd

So great to meet you! Hope to see you at the next one 😊

#GRS and #GRC #Archaea in the Swiss Alps: great meetings and location! Many familiar and even more new faces. Going home with exciting ideas and collaboration initiatives on exploring #archaeal #viruses in #soil! Thanks to everyone 😉

Meet Palaeocampa anthrax, a newly discovered Carboniferous lobopodian, and 150 year old mystery fossil!

Palaeocampa is an exceptional lobopodian - it lived in rivers and lakes, bristled with thousands of poisonous spines, and more. 🧵

Open access: nature.com/articles/s42...

🚨 FIRST PAPER ALERT 🚨

My first research paper I've been involved with is out now as a preprint 🦠🥳🦠

#archaea #microsky #PhD

And the story is published now!🍾
www.nature.com/articles/s41...

Open access link: rdcu.be/exnOc

Many years in the making, great collaboration with @archaellum.bsky.social & @tunglejic.bsky.social

Thanks @ukri.org BBSRC & @leverhulme.ac.uk for funding, reviewers & editor!! 🙏
#microsky #archaeasky

Elated to have our pre-print now published in @natcomms.nature.com #ArchaeaSky #Microbiology #MEvoSky
rdcu.be/euila
Our main results stay the same: S. islandicus follows a cell cycle akin to that of some eukaryotes, like the budding yeast, with cellular processes cycling similarly.
old🧵cited below👇

WitChi: Efficient Detection and Pruning of Compositional Bias in Phylogenomic Alignments Using Empirical Chi-Squared Testing Convergent evolution, where unrelated taxa independently evolve similar nucleotide or amino acid compositions, can introduce compositional bias into biological sequence data. Such biases distort phylo...

1.
🧵 New preprint out!
WitChi: a fast, open-source Python tool to detect, quantify & prune compositional bias in MSAs.
Lightweight, tree-free, scalable to 5k+ taxa... so we applied it to the GTDB archaea MSA.
#ArchaeaSky #MEvoSky #MicroSky
🔗 doi.org/10.1101/2025...
💻 github.com/stephkoest/w...

Excited to share our work on WitChi! 🛠️🖥️
We tested it on the GTDB r220 archaeal supermatrix (5,869 taxa & 10,101 cols) removing 55% of sites in <2h.

The phylogeny showed several interesting groupings with overall improved branch support:
#phylogenetics #ArchaeaSky #MSA #opensource #MEvoSky #MicroSky

Congratulations!!

Feeling very humbled by receiving this award and equally excited to attend ASM in Adelaide this year! 🎉

Excited to share our new paper in @cellreports.bsky.social that reshapes our understanding of chromosome organization's deep evolutionary roots! Our work dives into the origins of the machinery that structures our very genomes.

🔗: doi.org/10.1016/j.ce...

#Genomics #Evolution #CellBiology #LECA

Sensors pinpoint the exact time of a Yellowstone explosion Data could help to reveal the warning signs of potentially dangerous eruptions caused by liquid groundwater abruptly turning into gas.

A freshly installed network of sensors has pinpointed its first hydrothermal explosion at Yellowstone

https://go.nature.com/4jUnxhL

Eight Arms to Taste Your Microbiome

This is so cool - octopus can sense microbiomes: sending a gift link www.nytimes.com/2025/06/17/s...

over a year later, this one out today!

link.springer.com/article/10.1...

Abundant and metabolically flexible bacterial lineages underlie a vast potential for rubisco-mediated carbon fixation in the dark ocean - Genome Biology Background Rubisco is among the most abundant enzymes on Earth and is a critical conduit for inorganic carbon into the biosphere. Despite this, the full extent of rubisco diversity and the biology of ...

Abundant and metabolically flexible bacterial lineages underlie a vast potential for rubisco-mediated carbon fixation in the dark ocean genomebiology.biomedcentral.com/articles/10.... #jcampubs 🌊

Cyclic-di-AMP modulates cellular turgor in response to defects in bacterial cell wall synthesis - Nature Microbiology Brogan et al. uncover a signalling pathway in which levels of the nucleotide second messenger c-di-AMP increase in response to defects in cell wall synthesis. This regulatory pathway decreases turgor ...

🚨Out now!

Cyclic-di-AMP modulates cellular turgor in response to defects in bacterial cell wall synthesis @harvardmicro.bsky.social

#MicroSky 🦠

www.nature.com/articles/s41...

Deep Microbial Life Beneath Lavey-les-Bains Reveals Surprising Resilience - Marine Science Institute. The University of Texas at Austin. Beneath the warm, mineral-rich waters of Switzerland’s renowned Lavey-les-Bains Thermal Spa, the microbial world reveals surprising stability in the face of seasonal change. A new study published in…

Ancient microbes thrive beneath a Swiss spa—unchanged by the seasons.

New research with Dr. Mark Lever reveals deep underground life stays stable, even as Alpine waters shift above.

utmsi.utexas.edu/deep-microbi...

📸 Lavey-les-Bains

Very happy to finally have this out! Thank you to my awesome PhD supervisors and all the co-authors!!

Science Thrives on Trust: Why Collaboration Is Our Greatest Strength In a competitive academic world, building bridges instead of walls may be our most powerful tool to accelerate discovery and rebuild public trust in science.

"In a competitive academic world, building bridges instead of walls may be our most powerful tool to accelerate discovery and rebuild public trust in science."

I'm very happy with this article piece! 🥳

www.the-scientist.com/science-thri...

Congratulations!

Puri giving a short speech yesterday at the French Academy of Sciences to acknowledge her nomination as a new member. The fancy Napoleonic-style attire is part of the official Academy's protocol.
@academiesciences.bsky.social‬

The archaeal S-layer is not only pretty, it also carries crucial cellular functions, and the list keeps growing! @sshamphavi.bsky.social @marleenvw.bsky.social @archaellum.bsky.social and I wrote a little sheath sheet (+10 pts if you got the pun)
📖 Curr Opin Cell Biol
🔗 doi.org/10.1016/j.ce...

Marine Biology Career Advice You asked us questions about marine biology careers, and our panel of experts answered them! In April, I solicited your questions about careers in marine biology, and we received nearly 100 questio…

ICYMI: After years of hearing complaints that it's hard to get good career advice in marine biology, I assembled an expert panel to answer your questions about graduate school, where to find jobs, what skills are needed, and much, much more.

🦑🧪🌎🦈🐟

Expanding the cultivable human archaeome: Methanobrevibacter intestini sp. nov. and strain Methanobrevibacter smithii ‘GRAZ-2’ from human faeces Two mesophilic, hydrogenotrophic methanogens, WWM1085 and M. smithii GRAZ-2, were isolated from human faecal samples. WWM1085 was isolated from an individual in the United States and represents a nove...

🚨 New publication:
We describe a novel, cultivated #Archaea species from the human microbiome: #Methanobrevibacter intestini sp. nov. !
www.microbiologyresearch.org/content/jour...

#Microbiome #GutMicrobiota #NewSpecies #archaeasky #microbiomesky