Accumulation of arsenic in a unicellular alga Chlamydomonas reinhardtii

✍ Scribed by Toshikazu Kaise; Shoko Fujiwara; Mikio Tsuzuki; Teruaki Sakurai; Tohru Saitoh; Chiyo Mastubara

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 73 KB
• Volume: 13
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/(sici)1099-0739(199902)13:2<107::aid-aoc824>3.0.co;2-9

✦ Synopsis

The unicellular alga Chlamydomonas reinhardtii accumulated and biomethylated arsenic efficiently. A wall-less cell strain (CW-15) of Chlamydomonas reinhardtii proliferated in a low level arsenic-containing medium (0.01-0.1 mmol dm À3 ) more than that in an arsenic-free medium. Although the growth of the algal cells was only slightly more inhibited in a growth medium containing arsenic at a concentration of 1.0 mmol dm À3 than that in an arsenic-free medium, it was completely inhibited at concentrations of 10 and 100 mmol dm À3 . Furthermore, transformed strains were obtained by random introduction of plasmid pJD67, carrying an Arg gene, into a wall-less cell Arg À mutant CC425 strain. Finally we selected a strain, named AS1, among the transformed CC425 of the arsenic-sensitive group. The accumulation of arsenic by the AS1 strain was about three-fold higher than that by the CW-15 strain and 80-90% of the inorganic arsenic was transformed into a dimethylarsenic compound. It is suggested that the AS1 strain is a suitable model for investigation of the accumulation and biomethylation of arsenic by microalgae in freshwater environments.