Emrah Simsek

Our recent collaborative paper is now published in the latest issue of Cell Reports @cp-cellreports.bsky.social accompanied by a cover image highlighting how Bacillus gathers iron in the biofilm for promoting plant growth
www.cell.com/issue/S2211-...

Spatial proximity dictates bacterial competition and expansion in microbial communities - Nature Communications Here, the authors show that immotile bacteria degrade antibiotics to alter their environment and facilitate nearby motile competitors to expand. As expansion proceeds, the immotile degrader is outcomp...

Spatial proximity dictates bacterial competition and expansion in microbial communities

@natcomms.nature.com by @esimsek.bsky.social et al from @lingchongyou.bsky.social

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

8/8:
@lingchongyou.bsky.social
and I realized that, even though Klebsiella disappeared, it was indispensable for Pseudomonas to expand, serving as a hidden initiator. More in the paper for enthusiasts. Now, I continue this line of investigation in my own lab.

7/8: The study started when I tried altering Pseudomonas branching patterns by mixing it with Klebsiella. Expansion stopped well before the dish boundary, and I wanted to know why. My local CFU checks revealed Klebsiella was rare or absent in the final community.

6/8: Bacteria can kickstart spatial expansion under antibiotics and then vanish. Focusing only on dominant species captures the aftermath, potentially missing such hidden initiators.

5/8: Key biophysical insights:
1️⃣ An outsized role of minority bacteria
2️⃣ Context is key – effect cannot be captured in well-mixed cultures.
3️⃣ Proximity flips competition into facilitation – movement occurs only within helper-created safe zones.

4/8: First tested in a pairwise community (P. aeruginosa + Klebsiella) under cefotaxime. Then, using a sink-drain sample from a hospital room, we built SynkC, a synthetic community, showing the same phenomenon under carbenicillin.

3/8: We call these helper bacteria “hidden initiators.” They enable expansion by locally degrading antibiotics, creating safe zones where P. aeruginosa can move.

2/8: Unexpectedly, otherwise competing nonmotile bacteria can “rescue” P. aeruginosa if nearby. These helpers vanish quickly as P. aeruginosa outcompetes them.

Spatial proximity dictates bacterial competition and expansion in microbial communities - Nature Communications Here, the authors show that immotile bacteria degrade antibiotics to alter their environment and facilitate nearby motile competitors to expand. As expansion proceeds, the immotile degrader is outcomp...

1/8: In our new paper with
@lingchongyou.bsky.social doi.org/10.1038/s414..., we show that antibiotics don’t just kill bacteria—they can paralyze Pseudomonas aeruginosa at sublethal doses, halting its spatial expansion.

thanks for your kind words and for patiently reading it several times 😉

thanks for posting this.