I have been having some new issues with seeding NGM plates. The lawn looks fine, but when you look under the microscope you see these tiny dots/colonies growing on the lawn. When left out another day overnight they end up growing and becoming these larger viscous white spots but only stay on the e.coli lawn, they don’t grow anywhere else on the agar plate. I added strep and made sure to decontaminate the space, so if it is some sort of contamination I’m assuming it’s coming from the plate that has the single colonies I pick to inoculate.
Does anyone have an idea what this could be? Could it be that I left the plates out for too long/gave the bacteria too much time to grow on the plate?
I am starting over from the glycerol stock and new LB media, so I’m hopeful it should be gone with the next plates I seed. But I’m just more curious if others have seen something similar to this.