Best way to kill mold on wall before painting?
I'm a complete novice at painting and plan to paint my house interiors myself for the first time. I took down some wallpaper in a bathroom and a few days later some mold started growing in a small area. We had it professionally tested and luckily it was benign (Cladosporium and Penicillium). It's spreading a bit and I want to kill it in a manner that will prevent it from coming back before priming and painting. The bathroom has lathe and plaster walls, although we're patching some areas with new drywall.
I went to Home Depot and a paint dept employee told me to paint over it to "seal the mold in" because the paint chemicals would kill it. This does not sound correct to me. I'm thinking I should apply something topically to kill it before painting. I was going to use bleach but was warned that it isn't effective against mold on porous surfaces like walls.
I would appreciate any suggestions anyone could give on how to get rid of the wall mold permanently before priming and painting.