The New Hotel for Microbes

For a while now, it was thought that environments with low water activity would be too extreme for any type of microbial life. After the collection of oil samples in Pitch Lake, the world's largest natural asphalt lake, it was observed that in small bubbles beneath the oil surface were entrapped water droplets ranging from 1-3 microliters. When these droplets were analyzed, they observed that they sheltered microorganism, some of which were actively motile. Further analysis showed that the lack of essential nutrients was not a limitation for life in such environment. Now what kind of microorganisms can live in such conditions, you may ask? DNA sequencing demonstrated that there was a diverse composition among the bacterial communities, as shown in the figure below. 

From (Meckenstock, Rainer et.al. 2014). This figure shows the microbial community composition of the droplets analyzed. 

The metabolites of hydrocarbon degradation for bulk oil, droplet water, and water extracts were then analyzed to determine whether the microbes in the water droplets were actively degrading the oil. Organic molecules found in the water droplets reflected transformed oil constituents. The source of these organic molecules must have been biodegradation, which indicated that not only are these microbes living in these water droplets, but they also also actively degrading the oil. This discovery can be used to further research in cleaning up oil spills. 

Meckenstock R, von Netzer F, Stumpp C, Lueders T, Himmelberg A, Hertkorn N et al. (2014). Water droplets in oil are microhabitats for microbial life. Science 345:673-676.