Erm its Mycobacterium smegmatis, to come back to @evolvedbiofilm.bsky.social figure of sliding colonies we investigated the obviously odd one out (its not round or producing fronds) and found it was doing new additional things you normally do not see in sliding bacteria

Personally I think live in situ microscopy is critical when identifying motility as Henrichsen did when forming the definition of swarming twitching gliding etc in the first place pmc.ncbi.nlm.nih.gov/articles/PMC... (and its not done as much as it should be...)

note, gliding is not comparable to sliding

the here described spreading is very similar to sliding (=spreading by growth and facilitating compounds, like polysaccharides), which was known for Salmonella - the authors are not fully correct stating that sliding always depends on surfactant

M. smegmatis uses new types of biofilm to enclose a liquid core and expand outwards in a weird new way.

Artistic interpetation of a fluorescently tagged comet... Happy to talk to people about the S. aureus comet motility assay, if they need help with it etc

S. aureus organises itself differently in motile comet tips and can go uphill!