An interesting paper, concluding that the nanotubes of Bacillus result from membrane-compromised cells after application of compressive pressure. I wouldn& #39;t extrapolate from there to other organisms or no mechanical stress conditions. In Shewanella, for example, cell vitality 1/5 https://twitter.com/NatureMicrobiol/status/1312086031043301377">https://twitter.com/NatureMic...

was the first thing we tested when we observed the cytochrome-containing membrane extensions - Figure 1 in paper below. The timescale of the formation of these structures is > minutes rather than seconds as observed in the dying Bacillus cells 2/5 https://www.pnas.org/content/111/35/12883">https://www.pnas.org/content/1...

We also tested no shear stress conditions. In this recent paper, we observed membrane structures after surface contact in drop assays (no flow cells, no top contact etc). In rich media, we can even see some cells grow after vesicles/extensions, 3/5 https://www.frontiersin.org/articles/10.3389/fenrg.2019.00087">https://www.frontiersin.org/articles/...

I am no expert on the aspects of cargo delivery via nanotubes, but it also seems that the new paper does not address direct in vivo observations of cytoplasmic content movement, like cool paper below by @KostChristian (again no applied pressure!) 4/5 https://www.nature.com/articles/ncomms7238">https://www.nature.com/articles/...

So to make a long story short, I think it unwise to extrapolate across organisms, cell walls, Gram positive/negative, and applied stress.

All that said, we& #39;ll check with more experiments!

And finally, there is more exciting biophysics on all this in the pipeline 5/5