Microbes vs. Salt

lake-vida

Source: national geographic 2003

Even under the toughest conditions life tends to find a way. A great example of this are halophiles. Halophiles (from the greek word for “salt-loving’) are organisms that survive, live and even thrive in high salt concentrations.

Few organisms have adapted and occupied high salinity environments such as salt lakes, inland seas, and evaporating ponds of seawater. The ones that have adapted employ two different strategies to prevent desiccation (there may very well be more strategies, there is still much to discover*)

Strategies

First and most common is the accumulation of compatible solutes in the cytoplasm that serve as osmoprotectants. The second strategy is the selective influx of potassium ions into the cytoplasm.

A life-and-death struggle in the desert

The photo featured above shows salt crystals surrounded by halophiles is called “Microbe vs mineral: A life-and-death struggle in the desert’. When Michael Zach (chemist at the University of Wisconsin) went on a trip to Death Valley, CA., he took a salt sample. Back in the lab he added water to the sample. To his surprise the sample was swarming with microbes. These microbes originated form the original sample where they where in a dormant state, waiting for water to thrive once more. As the water evaporated the salt crystalized again (and Zach took this amazing image) The microbes seemed to secrete chemicals that prevented the growth of crystals, most likely they incorporated compatible solutes in their cytoplasm to prevent crystallisation. The mesmerizing rainbow of colors caused by the refraction of light by the growing crystals and the microbes fighting for their lives in the background got Zach’s image an honourable mention in the 2009 International Science and Engineering Visualization Challenge, sponsored by the journal Science and the US National Science Foundation (NSF).

*The ColonyTracker for research purposes allows to monitor and study these difficult to culture and even more difficult to study organisms. Don’t hesitate to contact us with your research idea!