Accumulation and Transformation of Arsenic in the Blue-Green Alga Synechocysis sp. PCC6803
2012
Yin, Xi-Xiang | Wang, L. H. | Bai, R. | Huang, H. (Hanson) | Sun, Guo-Xin
Synechocysis sp. PCC6803 is a unicellular blue alga which ubiquitously exists in aquatic system and is considered to play a role in arsenic cycling. Our results showed that Synechocysis can accumulate arsenic as much as 1.0 and 0.9 g kg−1 DW when exposed to 0.5 mM arsenate and arsenite for 14 days, respectively. In addition, arsenic species in cells were assayed under different exposure conditions and it was found that inorganic arsenic, including arsenate and arsenite, is the dominant species. Organic methylated arsenicals can only be detected exposed to higher arsenic concentration range (100–500 μM). Arsenate is the dominant arsenic species and presents more than 80% of the total arsenic in cells. Efflux of both arsenate and arsenite was observed. When treated with 2.67 μM arsenite, Synechocysis can rapidly oxidize arsenite to arsenate and accumulate As rapidly. The observed arsenic oxidation in solute is solely caused by cellular oxidation. Given the robust ability of As accumulation, it can serve as a phytoremediation organism to efficiently remove arsenic from aquatic environments.
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