Pearl strands of fluorescing anabaena

 Kingdom: Eubacterium
Scientific Name: Anabaena
Image Courtesy of: Shirley Owens, Laser Scanning Microscope Laboratory
Image Width: 23 microns
Image Technology: Laser Scanning Confocal Microscope

These beautiful strands are not pearls, but rather bacteria that provide us with an element even more valuable to our survival than pearls - namely nitrogen. Anabaena fixes nitrogen; it takes nitrogen gas from the air and binds it into protein molecules. Certain species of bacteria are the only organisms on Earth that are able to fix nitrogen. Since all living things require proteins to function, and since all protein molecules include nitrogen atoms, nitrogen-fixing bacteria play a major role in supporting life on Earth. These bacteria grow in rice paddies on the underside of Azolla ferns. The nitrogen they fix provides an important source of fertilizer for rice. Anabaena is a multi-talented organism; it is also able to create sugar that it uses for food via photosynthesis, just as plants do.