Table 1.

Gross estimates of surface area and SA/V ratios of modern osmotrophic unicellular megabacteria

Giant bacteriaLength, mmWidth, mmSA, mm2Volume, mm3SA/V, mm2/mm3Ref.
Achromatium oxaliferum0.1000.04501.98E-11.06E-41.9E+319
Beggiatoa spp.0.1600.05002.65E-12.09E-41.3E+319
Epulopiscium fishelsoni0.6000.08001.14E+03.00E-33.8E+216
Prochloron spp.0.0300.03002.83E-31.41E-52.0E+219
Sporospirillum praeclarum0.1000.00401.71E-28.38E-72.0E+419
Staphylothermus marinus0.0150.01502.83E-31.77E-61.6E+315
Thiomargarita namibiensis0.7500.75001.77E+02.21E-18.0E+016
Thiomargarita namibiensis0.001*8.82E-42.0E+316
Thiovulum majus0.0250.02501.96E-38.18E-62.4E+219
  • *An estimate of the effective SA/V ratio of Thiomargarita by assuming a 1-μm-thick layer of metabolically active cytoplasm surrounding a metabolically inactive central vacuole (16).