Scientists track chemical changes in cells as they endure extreme ...( One of nature's most gripping feats ...)

One of nature's most gripping feats of survival is now better understood. For the first time, scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory observed the chemical changes in individual cells that enable them to survive conditions that should kill them.

The team tracked the chemical changes in Desulfovibrio vulgaris, which is a single-cell bacterium that normally can only exist in an oxygen-free environment. They exposed the cells to the most hostile of conditions air and watched as some cells temporarily survived by initiating a well-orchestrated sequence of chemical events.

Until now, scientists have not been able to monitor, at a molecular level, the chemical changes in individual cells as they survive extreme conditions. The ability to watch this Herculean adaptation to stress, from such an up-close and real-time vantage, gives scientists an improved way to study adaptive responses in a range of microbes, such as disease-causing pathogens and microbes that play a role in photosynthesis, energy production, and geochemical phenomena. Their work was recently published online in the journal Proceedings of the National Academy of Sciences.

"We can now follow chemical changes in living bacteria as they respond to extreme environments. This opens up a new window into how bacteria adapt and carry out some of life's most important processes," says Hoi-Ying Holman, a staff scientist in Berkeley Lab's Earth Sciences Division.

To achieve this milestone, the team used the Advanced Light Source, a synchrotron and national user facility located at Berkeley Lab that generates bright light for scientific research. In a pioneering approach, they used a beamline equipped with a high-resolution infrared microscope to detect the molecular signatures of a cell's biochemical and metabolic activity, such as spikes in levels of free radicals and organic acids.

Specifically, the infrared micr
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