TAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Clostridia -> Clostridiales -> unclassified Clostridiales -> Epulopiscium
Epulopiscium is one of the largest known bacteria, a million times bigger than Escherichia coli or Bacillus subtilis. It is large enough to be seen with the naked eye at 600 µm. However, because it is so big, it must compensate for its surface-to-volume ratio, regardless of its nutrient-rich environment. It also has special coping mechanisms and structures within it, which were originally thought to be organelles. These structures form a cortex within Epulopiscium that are made of vesicles, capsules, and tubules that excrete and transport waste throughout the cell. The bacteria exhibit many unusual characteristics, mostly due to the adaptations necessary for their large size. Epulopiscium spp. are extremely polyploid, with bacterial chromosomes representing hundreds of thousands of copies of the genome.Since bacteria rely on diffusion rather than cytoskeletal transport as in eukaryotes, this extreme polyploidy allows for the production of gene products at numerous sites where they are needed in the cell.