E. coli able to detect arsenic

Could E. coli and homo sapiens become friends? True, the two are generally considered vicious enemies, but new research from the University of Edinburgh suggests reconciliation may be afoot. According to chemists at that pretigious Scottish university, E. coli can be used to test for trace amounts of arsenic in water. The end result could be simple field tests — as simple as a pregancy test, says one researcher — that might save millions of lives in underdeveloped nations. Indeed, preventing arsensic poisoning has been a major objective of the World Health Organization. Unfortunately, existing flouresence techniques used to detect the heavy metal are expensive and time consuming, and even field models require considerable training to operate properly.

The Edinburgh chemists take a different approach by relying on synthetic biology, an emerging subfield that mixes and matches genetic material to form unique biological functions within organisms such as bacteria. In the case of E. coli, the pathogen possesses a natural arsenic detoxification system that is switched on only in the presence of arsenic. Another set of genes breaks down lactose to produce acid. Having attached the two together, the researchers found that when arsenic comes in contact with the modified E. coli, the arsenic switch is activated, which in turn activates the breakdown of lactic acid. At that point, a simple pH test detects any change. And voila!

-read more in Jennifer Chu Technology Review report