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Estimated lowest theoretical size (diameter of sphere) for a free-living prokaryotic cell

Range	250 - 300 nm
Organism	prokaryote
Reference	Young KD. The selective value of bacterial shape. Microbiol Mol Biol Rev. 2006 Sep70(3):660-703 DOI: 10.1128/MMBR.00001-06 p.665 left column 2nd paragraphPubMed ID16959965
Primary Source	[227] National Research Council Space Studies Board. 1999. Size limits of very small microorganisms: proceedings of a workshop. National Academic Press, Washington, D.C.
Comments	P.665 left column 2nd paragraph: "Koch observes that the lower boundary of prokaryotic cell size is that which is “large enough to house the total amount of needed stuff” (ref 170). That is, the cell must have sufficient room to include all the nucleic acids, proteins, molecular complexes, and other gear required for survival and proliferation. By calculating the amount of space required to house this “needed stuff,” the lowest theoretical size for a free-living prokaryotic cell is estimated to be a sphere of 250 to 300 nm in diameter (primary source)."
Entered by	Uri M
ID	115571