Wednesday, September 19, 2007

Thermophiles: Heat lovers

So the blog moves from bison, some of the larger organisms in Yellowstone, to the thermophiles, some of the smallest. Yellowstone National Park was originally set aside due to the geologic wonders in the area. Who knew at that time that in the hot springs, geysers, and mudpots there were heat (and in some cases acid) loving organisms?
One can somewhat determine the temperature of the water by the color of the bacterial and algae mats. Algae can't stand the hottest water, so the green growth tends to be in cooler areas of the runoff. The thermophilic algae species Cyanidium, is an autotroph which means it does photosynthesis to use the energy of the sun to make food. It can survive in temperatures from 100-133 degrees F (38-56 degrees C). Many of the bacterial species are "chemotrophs" which extract energy from chemicals in the water such as iron and sulfur. One species of bacteria converts hydrogen sulfide to sulfuric acid in the process. These bacteria, in addition to being thermophiles, are also called acidophiles or acid lovers.While this may look like an aerial photo of a landscape, it is a mat of bacteria and algae. In some ways it is a micro-landscape with its own micro food web. There are flies that feed on the algae and bacteria called Ephydra flies. In turn they are fed upon by wolf spiders which are eaten by dragon flies, and the dragon flies feed a variety of birds such as killdeer. During the early spring as birds begin to fly into the park, these hot spring food webs may be their only source of food.
Some of the mats are thick enough to support the weight of small animals. The number of thermophiles living in a 10 inch square can exceed the number of people (over 6 billion) on Earth.
The colors of the bacteria indicate something about their ability to withstand heat. The brighter the color, the hotter the environment the organism can tolerate.
The photo above was taken at the Grand Prismatic Spring. The spring is the largest hot spring in diameter at Yellowstone. It is 120 feet deep and 370 feet across. There is no way to capture the true beauty of the spring except by air so I took a picture of one the interpretive signs to share that view with you.

Dr. Thomas Block was one of the first people to do research on the bacteria found in the hot springs. He started back in the 1960's. Today, enzymes produced from these bacteria are used for a variety of purposes. One enzyme from Thermus aquaticus is used as the driver of the reaction used in DNA fingerprinting.
In addition to the hot springs there are mudpots in which kaolin is dissolved to make clays. The mudpots are hot, and range from "soupy" to "ploppy". I have some video of these I will work on and post later.

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