Calculated and measured values for buoyant densities of bacterial cells and bacterial pellets

Range Table - link g/cm^3
Organism bacteria
Reference Bratbak G, Dundas I. Bacterial dry matter content and biomass estimations. Appl Environ Microbiol. 1984 Oct48(4):755-7. p.756 table 2PubMed ID6508285
Method p.755 right column top paragraph:"The harvested cells were resuspended in glucose-free medium with 3H marker for 30 min or with 14C marker for 2 min and then centrifuged at 12,000 x g for 10 min."
Comments P.756 left column 3rd paragraph: "From literature data on bacterial cell content of protein, DNA, RNA, lipid, carbohydrate, and ash (refs 13, 20), and data on the specific gravity of these compounds (refs 1, 2, 20), one may estimate the specific gravity of bacterial dry matter to be in the range of 1.35 to 1.6 g/cm^3 [BNID 114795]. Based on these estimates and on [investigators’] experimentally determined values for percent dry weight of cells, [they] have calculated the theoretical buoyant densities of bacterial cells. These calculated values were, in general, slightly higher than the buoyant density values determined by direct experimentation (Table 2)." Caption to table 2: "The cells and pellets used for determination of buoyant densities were prepared under conditions identical to those used for determination of percent dry weight of the pellets and percent intercellular water in the pellets. Average values for percent dry weight of cells and pellets and percent intercellular water in the pellets (from Table 1 BNID 108223) were used for calculation of buoyant densities."
Entered by Uri M
ID 112013