PMC

Phylogenic position of experimental organisms in the schematic phylogenetic tree of life (phylum-level). Star, phylum including strains examined in this study; A, H and A/H, nutrient condition indicating mostly autotrophic, mostly heterotrophic and mixture of A and H, respectively

Elimination ability of radionuclides from the culture medium by algae and aquatic plants in the primary (global) screening. a ¹³⁷Cs; b ⁸⁵Sr; c ¹²⁵I. Average values are ranked in descending order. List of all organisms and values are the same as those listed in Table S1. Seawater strains ranked within top 20 in each radionuclide are marked by asterisks

Comparison between the abilities of selected strains to eliminate two different radionuclides in the radionuclide elimination test. a ¹³⁷Cs vs. ⁸⁵Sr; b ¹³⁷Cs vs. ¹²⁵I; c ¹²⁵I vs. ⁸⁵Sr. Strains: A nak 8; B nak 9; C nak 1001; D nak 1002; E NIES-1458; F NIES-1956; G NIES-2131; H TIR 3; I TIR 4; J We 2; and asterisk unicellular strain. The names of strains are listed in Figs.  and (See also Table S1)

Fractionation of radionuclides from the strain culture medium. After incubation with ¹³⁷Cs (a), ⁸⁵Sr (b) and ¹²⁵I (c) for 8 days, the radioactivity recovered in the cells (open bar), the precipitates (hatched bar) and the soluble materials (closed bar) from the medium was determined. The names of strains are the same as shown in Fig. , except nak 8 (Ophiocytium sp., Ochrophyta) and TIR 4 (Nostoc commune, Cyanobacteria) (See also Table S1). All these strain codes are underlined in Table 

Effect of potassium on the ability of the eustigmatophycean strain nak 9 to eliminate radioactive Cs. Algal cells were firstly grown in the potassium-deficient AF-6 medium for 14 days and then transferred to the fresh medium containing ¹³⁷Cs (10 MBq l⁻¹). Various concentrations of potassium phosphate were added at 4 h, as indicated by an arrow. Elimination of ¹³⁷Cs from the medium was determined by the silicone-oil-layer-centrifugation method, as described in “”. Final concentration of potassium (mg l⁻¹): Closed circle 0 (control); triangle 1.25; diamond 2.5; ×-mark 5; square 10; open circle 25

Elimination ability of radionuclides from the culture medium by selected algae and aquatic plants in the second screening. a ¹³⁷Cs; b ⁸⁵Sr; c ¹²⁵I. Opened, hatched and closed bars represent values of percent elimination after 2-, 4- and 8-days incubation, respectively. The values (ng g DW⁻¹) indicate the mass of radionuclides accumulated/recovered by cells during 8 days (calculated on the basis of dry weight). The names and strain codes (marked with underline) are the same as those listed in Table . Others are as followings: AYCC145, Bangia sp., Rhodophyta; AYCC550, Bangiopsis sp., Rhodophyta; DA 36, Heterosigma akashiwo, Ochrophyta; INB 97, Coelastrum sp., Chlorophyta; nak 13, Tetraselmis sp., Chlorophyta; nak 15, Tetraselmis sp., Chlorophyta; nak 27, Calyptrosphaera sphaeroidea, Haptophyta; nak 1003, Spirogyra sp., Zygnematophyta; NIES-329, Ulothrix variabilis, Chlorophyta; NIES-548, Acinetospora crinite, Ochrophyta; NIES-931, Gloeocapsa decorticans, Cyanobacteria; OS 4, Dixoniella grisea, Rhodophyta; TM 16, Amphidinium massartii, Dinophyta; and We 3, Eleocharis acicularis, Tracheophyta (See also Table S1). Strains We 4 and OS 4 were additionally tested in this screening. Seawater strains are indicated by asterisks