Bacteria save the world!

Ok, it's a rather dramatic tabloid-style headline, but as Mark has already pointed out we have a great deal to be thankful to bacteria for. If to 'save the world' means allow it to be habitable for human life, then we already owe bacteria many times over. However, rather than the natural development of ecosystems, which has been going on for millennia (no matter what those Young Earthers are saying) what I'm referring to here is much more recent: the intentional use of live microbes as an army of ingenious chemists to help solve current human problems in a sustainable way. This is one of those interesting ideas that occupies my mind now and then, on the drive home from work, or even while at work when I'm supposed to be doing something else...