Sebastian Schmidt
tsbschm.bsky.social
Sebastian Schmidt
@tsbschm.bsky.social
Lecturer in Microbiome & Health at @apcmicrobiomeirel.bsky.social & @ucc.bsky.social

Alumnus @borklab.bsky.social

Microbiome, microbial ecology & metagenomics.
IYKYK...
November 6, 2025 at 4:11 PM
Together, these dbs allow one to address 'big' questions in microbial ecology & evolution with 'big' data, at unprecedented scales.

Give it a try, and feedback is always welcome!
October 31, 2025 at 3:24 PM
[while the inner monologue goes...]
October 28, 2025 at 3:28 PM
"As a scientist, how do you feel about the US Secretary of Health?"
October 28, 2025 at 3:25 PM
🫣
October 23, 2025 at 9:05 AM
“It’s more of a comment than a question…”
October 9, 2025 at 4:26 PM
Fun party game idea.

Guess the researcher based on G Scholar citation stats:
August 5, 2025 at 12:42 PM
Guilty as charged...

But also quite literally. I once put this as a biosketch into a talk:
July 16, 2025 at 7:54 AM
This is a view across marker genes when we go back with the inferred conversion factors (slopes) and re-predict species counts. Y axis is deviation (1 - rho).

NB: `spire.species` are GTDB classifications (only) for SPIRE MAGs, `spire.ani` is just 95% clusters of SPIRE MAGs as a "species" equiv.
July 1, 2025 at 6:34 AM
@benjwoodcroft.bsky.social so this is an example for a (random) archaeal marker. X axis is n of clusters, y axis is n of species; it's rarefied based on n of genomes considered. It's quite linear and quite close to slope=1 (give or take across markers).
July 1, 2025 at 6:34 AM
We estimate that ~10 novel archaeal and ~145 bacterial phyla are "hiding" among the unbinned contigs. This corresponds to an increase of ~50% and ~83% relative to ref dbs.

For genera, we find that >3 novel genera are discoverable per each recognized genus in the reference.
June 27, 2025 at 8:10 PM
Finally, we built >130 large marker gene phylogenies and cut them at relative evolutionary divergence (RED) levels corresponding to phylum-, class-, order-, family- and genus-level clades.

(dots in the plot below indicate phyla and families)
June 27, 2025 at 8:10 PM
This becomes even clearer in an "incremental" rarefaction analysis. Although human-assoc and gut samples account for >2/3 of samples in the survey, they only contribute 1/3 of total discovered diversity.

Most unbinned species species lurk among soil, aquatic & wetland samples.
June 27, 2025 at 8:10 PM
Given SPIRE's curated sample annotations, we broke these numbers down by habitat. We calcualted a 'species discovery coefficient' α.

Few habitats show signes of saturation (no new sp. added as more samples come in, α≤0). Most, in particular soils & aquatic envs, remain in full discovery swing.
June 27, 2025 at 8:10 PM
After clustering these to (calibrated) species-level groups for each marker, we could then build "species discovery" (or rarefaction) curves across 92k metagenomes from SPIRE.

We estimate that ~702k bacterial and ~27k archaeal species are "discoverable" in total in these contigs.
June 27, 2025 at 8:10 PM
When yet another 16S-based paper discusses analyses of “strains”.
June 19, 2025 at 11:08 AM
The Koonin Law of Computatoinal Biology:

Whenever you think you have a great idea in computational or evolutionary biology, it will already have been published by Eugene Koonin in the mid 90ies.
June 3, 2025 at 12:31 PM
Same energy. #IYKYK
May 3, 2025 at 2:17 PM
Another week with 5 peer review invites (and counting).
April 9, 2025 at 9:14 AM
In this spirit I’m stealing this meme:
April 8, 2025 at 11:00 AM