Bacteria anticipate coming events
Just as humans have learned to connect dark clouds with rain, so too have bacteria and yeast learned to use one event to predict the arrival of another.
"For multicellular organisms, there is a real benefit to understanding the temporal order of things," says Amir Mitchell, a scientist at The Weizmann Institute of Science in Israel.
"If you see clouds you might expect rain, and take an umbrella out with you," says Mitchell, who is also co-author of a paper that appeared in the journal Nature.
The two organisms studied in the research, Escherichia coli, which can travel through the human digestive tract, and fermenting yeast, Saccharomyces cerevisiae, used by winemakers to turn sugar into alcohol for thousands of years.
In the human digestive tract, sugar lactose is present before sugar maltose. Introducing E. coli to lactose not only triggers genes that let the bacteria metabolise lactose, but also initiates the expression of genes that produce enzymes that can metabolise maltose.
No maltose is yet present, but the bacteria are now equipped to metabolise maltose when they are exposed to it.
In wine bottles, yeast must withstand the heat produced during fermentation and then the chemical pressure of oxidation. As the bottles heat up, the yeast activate genes that allow them to survive the heat.
This also triggers the activation of genes that enable the yeast to survive oxidation, the next stage of the fermentation process.
30 June 2009 Eric Bland
Taken from the ABC website Read more