volume 0.4µm^3 15.2%: volume 0.026µm^3 46.5 %
||Meinhard Simon, Farooq Azam, Protein content and protein synthesis rates of planktonic marine bacteria. Marine ecology progress series. Oldendorf, 1989 Vol 51 pp.201-213 abstract and p.207 right column bottom paragraph
||Abstract: "[Investigators] measured bacterial protein content and protein production of pelagic bacteria. Bacterial protein content was measured as amino acids by high performance liquid chromatography of cell hydrolysates of bacterial assemblages of mean diameters [note: this should probably read 'volumes'] from 0.026 to 0.4µm [should probably be 'from 0.026 to 0.4µm^3']."
||Abstract: "Cellular protein:volume (w/v) in the largest bacteria was 15.2% (similar to cultured Escherichia coli) but increased with decreasing cell size to 46.5 % in 0.026µm bacteria. Protein per bacterium was correlated with cell volume by the power function y = 88.6x^0.59 (r^2 = 0.67, p<0.01, n = 25)." P.207 right column bottom paragraph: "The power-function relationship between cell volume and protein (Fig. 2) shows that as the cells become small the protein:cell volume ratio increases greatly (Table 5). [Investigators’] smallest bacteria (0.026 µm^3) had 465 mg protein/ml cell volume while this value decreased to 152 mg protein/cell volume in 0.4 µm^3 bacteria, similar to that reported for Escherichia coli cultures (Ingraham et al. 1983). Clearly, there is a large and progressive increase in protein 'concentration' as bacteria become smaller."