Using fluorescence, x-ray, and electron microscopy in conjunction with genome sequencing, researchers at the Genomic Institute of the Berkely National Lab characterized Thiomargarita magnifica, a bacterium with an average cell length greater than 9,000 µm that is visible to the naked eye and is over the theoretical limits of bacterial size.

     T. magnifica grows as a white filament on the decaying leaves in Caribbean mangroves in Guadeloupe, Lesser Antilles. It is a single cell with a thread-like body. On average, the T. magnifica bacteria reaches up to 9,000 micrometers, with the largest reaching the 2 centimeters and is visible with the naked eye. The morphology of the T. magmifica filaments observed from Guadeloupe resembled those of sessile Thiomargarita-large sulfur bacteria-like cells reported from deep-sea methane seeps.   EM's of T.magnifica*.

     Staining revealed DNA in T. magnifica cells was concentrated in membrane-bound granules and not spread throughout the cytoplasm, as is common in bacteria. No bacteria or archaea are known to unambiguously segregate their genetic material in the manner of eukaryotes,

     DNA sequencing show some 11 million base pairs and an estimated 11,000 genes, 3 x the size of most bacterial genomes. T.m's genome is highly repetitive copies of some sequences reminiscent of more complex life forms.