Cannibalistic Plants May Fuel the Future
November 26, 2012
Animals often feed on plants, and some plants even feed on animals. But researchers have recently identified the first plants that feed on other plants. The cannibalistic plants are green algae, which scientists classify as Chlamydomonas reinhardtii. Although algae are not true plants, green algae are close relatives that ordinarily make their own food through photosynthesis. In photosynthesis, plants and similar organisms use the energy in sunlight to combine water and the gas carbon dioxide, forming sugar. However, the freshwater algae C. reinhardtii often live in the soil, where they may not have access to sunlight and carbon dioxide. Under those conditions, the algae switch to feeding on plant matter in the soil.
The plant matter the algae feed on is cellulose, a tough material in the walls of plant cells and many kinds of algae. Cellulose is a long chain of sugars. The algae release a chemical called an enzyme that can break cellulose apart into simple sugars. The algae then consume these sugars for food.
Scientists have identified many plants that live as parasites on other plants. These plants steal nutrients, often by taking the juices of another plant. But the green algae are the first plantlike organisms known to dissolve cellulose, which makes up the body of the plant itself. Previously, only certain bacteria and fungi were thought to have this ability. Researchers suspect that other kinds of algae may also be able to dissolve cellulose.
The discovery may prove useful in efforts to produce biofuels. Biofuels are fuels made from living things that can be regrown quickly. Thus, biofuels are renewable fuels, unlike such fossil fuels as coal and oil. Much research into producing biofuels has focused on growing algae. However, processing the algae into fuel requires using expensive chemicals to dissolve cellulose. An alga that can dissolve cellulose might make biofuel cheaper to produce, helping biofuels to compete with fossil fuels.
The research was led by Olaf Kruse of Bielefeld University in Westphalia, Germany. It was published in the November 20 issue of the journal Nature Communications.
Additional World Book articles:
- Lichen
- The Green Gold of Algal Biofuel (a Special Report)