OBJECT OF THE MONTH - August, 2009

Diatoms from Colorado: First peeks find new discoveries among the peaks


What are Diatoms?
Diatoms are microscopic, photosynthetic organisms that have chlorophylls a and c, which puts them in a lineage of organisms called stremenopiles, apart from the "plant" lineage of green things we normally think of as being photosynthetic.
Diatoms have glass cells walls (they take dissolved silicon dioxide out of the water and make their cell walls amazing!), which have a variety of perforations through the walls. The perforations, many times arranged in symmetrical patterns, allow the diatoms to exchange materials with their environments (take up nutrients, get rid of metabolic wastes).
How are diatoms important?
Diatoms are found in almost all aquatic environments: marine, estuarine and freshwaters. They are the base of the food chain in these ecosystems (the preferred food source in experimental studies), and since they take up carbon dioxide and evolve oxygen through their photosynthetic activities, they help reduce greenhouse gases and provide oxygen. In fact, as a group, they produce more oxygen than all the rainforests combined (remember the earth is 2/3 water). Some even think diatoms could help reduce the effects of global warming).
Unlike those green photosynthesizers, instead of storing starch as the by-product of their photosynthetic activities, diatoms store a lipid (or oil). They are now the focus of intense research as a new source of biofuels.
The intricate designs of their glass cell walls are also making diatoms interesting to engineers interested in nanotechnology (remember computer chips are silicon).
Diatoms from Colorado
Amazingly, there are few reports of diatoms from the Rocky Mountain region, especially Colorado. Aside from a few mentions in ecological studies (diatoms also make great water quality indicators), there have been no taxonomic treatments of the diatoms from Colorado.
A short trip up to Peaceful Valley in Boulder County yielded 4 new species of diatoms, and material to describe a new genus as well! The first new species of higher plants were described from Colorado over 150 years ago, so we have a lot of work to do working with microbes just to get a baseline of the diversity present in our state. Our lab continues to collect diatoms from the state, and we will continue to document the diversity of this amazing group of organisms in Colorado. Stay tuned for news of additional discoveries.
To Learn More
Could Tiny Diatoms Help Offset Global Warming?, Science Daily, Jan. 26, 2008.
Stramenopiles, Tree of Life Web