The largest-known bacterium is changing researchers' ideas about what is possible for bacteria, Earth's most ancient life form.The organism was discovered on the Caribbean island of Guadeloupe and is big enough to be seen with the human eye.Scientists said recently that the bacterium, called Thiomargarita magnifica, is unusual for its size -- up to about two centimeters long.It is also notable because its structure is unlike other bacteria.The DNA, an organism's genetic information, is not free-moving inside the cell like in most bacteria.Instead, the DNA is contained within many small membrane-bound sacs.Membrane-bound structures in cells are called organelles.Jean-Marie Volland was a co-leader of the study that appeared in the publication Science.Volland said of the bacteria, "It is thousands of times larger than regular-sized bacteria.Discovering this bacterium is like encountering a human being as tall as Mount Everest.”Researchers have found the bacterium in several places in Guadeloupe, a French island group in the Caribbean.
