Bioaccumulation of Antimony by Chlorella vulgaris and the Association Mode of Antimony in the Cell

✍ Scribed by Shigeru Maeda; Hideto Fukuyama; Emi Yokoyama; Takayoshi Kuroiwa; Akira Ohki; Kensuke Naka

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 135 KB
• Volume: 11
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/(sici)1099-0739(199705)11:5<393::aid-aoc593>3.0.co;2-7

✦ Synopsis

The bioaccumulation and excretion of antimony by the freshwater alga Chlorella vulgaris, which had been isolated from an arsenic-polluted environment, are described. When this alga was cultured in a medium containing 50 g cm Ϫ3 of antimony(III) for 14 days, it was found that Chlorella vulgaris bioaccumulated antimony at concentrations up to 12 000 g Sb g Ϫ1 dry wt after six days' incubation. The antimony concentration in Chlorella vulgaris decreased from 2570 to 1610 g Sb g Ϫ1 dry wt after the cells were transferred to an antimony-free medium. We found that the excreted antimony consists of 40% antimony(V) and 60% antimony(III). This means that the highly toxic antimony(III) was converted to the less toxic antimony (V) by the living organism.

Antimony accumulated in living Chlorella vulgaris cells was solvent-fractionated with chloroform/methanol (2 :1), and the extract residue was fractionated with 1% sodium dodecyl sulfate (SDS). Gel-filtration chromatography of the solubilized part showed that antimony was combined with proteins whose molecular weight was around 4ϫ 10 4 in the antimony-accumulated living cells.