I'm going to assume you're talking about random happy bacteria/fungi... (?)
The boil is more than just to sanitise the wort, it will also drive off DMS (Dimethyl Sulfide), which in too great a quantity will result in your fermented beer smelling (but not necessarily tasting) of creamed corn.
This may or may not be followed by the sound of manly weeping as you tip 26L of bottled beer down the drain because you didn't know about boiling your wort yet. I'm also going to pretend this never happened.
Give "Dimethyl Sulfide" a go in your favourite search engine and click on the beer related links to find out more...
Mick