What is the 0.01% of bacteria that soap doesn’t kill?

LAST MODIFIED: May 31 2018, 10:33 IST

Is this just accounting for some undiscovered bacteria or something?We all have doubts entangling in our minds since the advertisers themselves have placed i our consumer brain. So here we provide the answer.

Best answer, lucky bacteria. Soap is a detergent. A common detergent in handwashing soap is sodium dodecyl sulfate. SDS is used to kill because it has both polar and nonpolar properties. Thus, it is able to get into the membrane of a cell, which itself as a polar and nonpolar end (and lined up, you get a nonpolar core and a polar exteriors to the membrane’s envelope.) SDS gets in there and causes the disruption and dispersion of the lipids, meaning the cell spills its guts. Cells don’t live once they spill their guts.

Some cells~~, for reasons that aren’t understood,~~ are just lucky. Maybe the local soap concentration was low, maybe the exposure was low. Maybe they’re particularly hardy as a species (those exist). They’re just lucky.

Of course, you can always use harsh detergents (the kind used in fracking) to really chew up hardy critters, but those are also irritants for us (our cells will rupture, too, but we have a nice thick integument – our skin), so you’d probably not want to wash with those.