Bacteria

Bacteria are usually the most numerous of soil microorganisms. They have an extremely varied metabolism. Bacteria can use reduced inorganics, the sun, or organics as an energy source. Some bacteria can live without free molecular oxygen. Soils often have between 1,000,000 to 10,000,000 bacteria per gram. The end of the movie shows a soybean nodule containing bacteria that fix nitrogen.

Close window to return to Movie Homepage.