Make 'em happy

摘要

Scoop up a handful of dirt or wipe the inside of your cheek with a cotton swab. Not impressed? You should be. What you have there are the enigmatic rulers of the world. You can't see them, but they make up more than half the living mass on Earth. They have the power to save lives or make us seriously ill, as well as to protect crops from sickness and droughts. They even play a large part in controlling the climate. And nearly all the antibiotics in use today have come from them. They are, of course, microbes. But given how important they are, it is surprising how little we know of them. Imagine you were to sprinkle that random pinch of soil on to a Petri dish, that classic nursery for microbes. Not even 1 per cent of the bugs will grow. Without a thriving colony, it's next to impossible to study a bacterium. So there is no escaping the fact that most of what's out there is microbial dark matter - its identity shrouded in mystery, like the strange stuff that makes up most of the cosmos.