Discovered in 1999 off the coast of Namibia, Thiomargarita namibiensis has the distinction of being the largest bacterium in the world, at a remarkable volume of 3 million times that of a normal bacterial specimen. The long string of cells, named "Sulfur pearl of Namibia" because of the reflective white globules of sulfur contained in them, was found buried in the sulfur-abundant sea floor. Each ball-shaped cell can grow up to nearly 1 milimeter in diameter--a measurement usually taken in microns. Because of some unique adaptations, Thiomargarita namibiensis is able to survive in a high-sulfur environment with little or no oxygen. Each individual bacterial cell is almost entirely made up of a liquid vacuole, in which is contained large amounts of nitrate, often 10,000 times the amount in the surrounding seawater.
Via Dr. Stefan Gruenwald