“WOW! Brilliant! Gorgeous! Stunning! I can’t believe these colors! Oh, I’ll just take one more photograph—-well, make that another twenty photographs—-before I have to move on!” During a late Spring visit to the crown jewel in the United States’ national park system, Yellowstone National Park, I quickly ran out of superlatives to describe the vibrant colors associated with Yellowstone’s geothermal hot spring and geyser features. My eyes and memory chips could not get enough of their abstract compositions and beauty.
Grand Prismatic Spring and bacterial mats, Yellowstone National Park
Grand Prismatic Spring, Yellowstone National Park. The vivid coloration ringing this magnificent geothermal pool is the produce of thermophilic bacteria.
Situated atop a massive seething volcanic caldera, Yellowstone National Park generates endlessly fascinating geothermal volcanic phenomena. Volcanic features ranging from eruptive geysers to roiling, boiling mudpots, roaring steamy fumeroles and hot pools so vibrantly colored they defy description demonstrate the raw beauty of Nature. What particularly impressed me are thermophilic bacterial features associated with geothermal activity. Thermophiles are heat-loving organisms that survive in temperatures ranging from 45 degrees C (113 degrees Fahrenheit) to as high as 80 degrees C (176 degrees Fahrenheit).1 Intensely hot water runoff laden with chemicals and minerals from volcanic thermal springs and geyser eruptions creates a happy haven for thermophilic bacteria, the organism responsible for much of the brilliant coloration found in and around Yellowstone’s geothermal features.
Biscuit Basin thermophilic community, Yellowstone National Park
Developing in a variety of forms, thermophiles organize into communities such as streamers, “long, flexible structures…in the fast-flowing water of runoff channels”2 or “mats or layers of archaeal and bacterial communities that are adapted to specific temperature and light conditions within the mat. Thermophylic bacteria and archaea are often brightly colored by photosynthetic pigments (chlorophylls or carotenoids) and show distinct zonations according to their specific temperature tolerances.” 2 (Note: archaea are “ancient microorganisms that some scientists now regard as a separate kingdom of life.”)4 Hot springs’ polychromatic bacterial mats sported vivid hues of rust, ochre, lemon yellow, olive green and black that attest to thriving communities of thermophiles.
Thermophilic feature at Biscuit Basin, Yellowstone National Park
The first thermophile to be recognized, Thermus aquaticus was discovered in 1966 by Dr. Thomas Brock living in a hot spring in Yellowstone National Park. Since then, many other thermophilic bacteria have been identified in environments ranging from geothermal pools to fumaroles to deep sea volcanic vents. Depending not only in excessively hot life-giving water, some of these amazing microorganisms prosper where there are “high levels of sulfur or calcium carbonate, acidic water, or alkaline springs,” 3 for instance, an active geothermal environment such as Yellowstone.
What makes thermophiles particularly valuable to biotechnology and us are their extremozymes, enzymes adapted not to break down in high heat. Unlike other less tolerant enzymes that would catastrophically collapse in a high heat environment, extremozymes enable thermophilic cell membranes to remain stable even when subjected to extremely high temperatures. 3 This has proven invaluable to many things we depend upon today, from high heat washing agents to soft drink sweeteners to DNA fingerprinting.
Sunset Lake, Black Sand Basin, Yellowstone National Park
Dazzled by spectacular Old Faithful and other geysers’ eruptions, it is easy to simply walk past these lowly yet colorful geothermal thermophiles without giving them much of a passing nod. Recognizing the biotechnological importance of lowly thermophilic bacteria brings a new level of appreciation to gazing onto the multi-colored beauty of Yellowstone’s geothermal features. Yet for me, I confess to happily leaving science behind for a moment to savor the vivid coloration and pattern of thermophilic features that evoke a deeply enthusiastic “WOW!”
Black Pool, West Thumb Geyser Basin, Yellowstone Natiional Park. The white geyserite, or sinter—-“a mineral deposit with a porous or vesicular texture” 5—-provides counterpoint to the orange bacterial mat and vivid turquoise of the hot spring.
1) “Thermophile,” WIkipedia, http://en.wikipedia.org/wiki/Thermophile
2) “Yellowstone National Park,” Microbial LIfe Educational Resources, http://serc.carleton.edu/microbelife/extreme/ex...
3) Heather Beal, Montana State University, “Microbial Life in Extremely Hot Environments,” Microbial LIfe Educational Resources, http://serc.carleton.edu/microbelife/extreme/ex...
4) “Forecast: Hot and humid,” Brave New Biosphere, http://whyfiles.org/022critters/hot_bact.html
5) Britannica Online Encyclopedia, http://www.britannica.com/EBchecked/topic/54630...