Bacteria can anticipate future illnesses, study finds

REHOVAT, Israel Israeli scientists from the Weizmann Institute of Science last week released a report suggesting that bacteria can anticipate a future event and prepare for it.

In a paper that appeared June 17 in Nature, researchers determined that the microorganisms' genetic networks are hard-wired to "foresee" what comes next in the sequence of events and begin responding to a new state of affairs before its onset.

E. coli bacteria, for instance, which normally cruise harmlessly down the digestive tract, encounter a number of different environments on their way. In particular, they find that one type of sugar – lactose – invariably is followed by a second sugar – maltose – soon afterward. Yitzhak Pilpel, professor at Weizmann Institute of Science, and his team of the Molecular Genetics Department, checked the bacterium's genetic response to lactose and found that, in addition to the genes that enable it to digest lactose, the gene network for utilizing maltose was partially activated. When they switched the order of the sugars, giving the bacteria maltose first, there was no corresponding activation of lactose genes, implying that bacteria have naturally "learned" to get ready for a serving of maltose after a lactose appetizer.

Another microorganism that experiences consistent changes is wine yeast. As fermentation progresses, sugar and acidity levels change, alcohol levels rise and the yeast's environment heats up. Although the system was somewhat more complicated than that of E. coli, the scientists found that when the wine yeast feel the heat, they begin activating genes for dealing with the stresses of the next stage. Further analysis showed that this anticipation and early response is an evolutionary adaptation that increases the organism's chances of survival.