Blindfold any bacteriology scientist and ask them to smell agar plates containing Pseudomonas aeruginosa, Haemophilus influenzae and Streptococcus anginosus respectively. Chances are they will give you the ID in a flash.
I am not suggesting you do this however! We would never smell plates for Health and Safety reasons, but sometimes it is difficult not to get a whiff in passing….
Along the same lines think about how a Moraxella catarrhalis moves over the surface of the agar when you give it a prod with a loop. Think about how a Eikenella corrodens buries itself into the agar…
Why am I telling you all this?
In a few months time my lab will be getting a Kiestra TLA system where the plates will no longer be hand held for visual inspection, but digitally imaged for viewing on a screen. No longer will the scientists be able (routinely) to smell the plates or move the colonies about with a plastic loop.
Some might say that this is a disadvantage when it comes to recognising bacteria. Maybe, but I believe the other advantages of moving to this sort of system far outweigh losing the ability to touch and smell the bacteria.
And if you really wanted to, you could ask the Kiestra to “call” the plates to your workbench so you can use “other senses” apart from your eyesight. I suspect this might happen quite a lot to start off with, and then become less and less common as staff gain confidence in the system.
And maybe in 20 yrs time, when everybody, everywhere, has TLA systems, we will all forget what a Pseudomonas or a Haemophilus smells like, but I doubt it….