Can gene editing deliver on its promise?

In early 2005 Rodolphe Barrangou and Philippe Horvath were staring at some very odd bits of repeating genetic code on a computer screen in France. The sequences came from Streptococcus thermophilus, a bacterium that, like other bacteria, often skirmishes with viruses. Rumour had it that these sequences of DNA might help bacteria gain the upper hand in the fight. If they did, the researchers wanted to know all about it. S. thermophilus is one of the microbes used to make yogurt. Stopping it from falling prey to viruses would save Danisco, the foodmaker they both worked for at the time, millions of euros.