Iodate respiration by sp. DN11 and its potential use for removal of radioiodine from contaminated aquifers

Sasamura, Seiya*; Onuki, Toshihiko*; Kozai, Naofumi   ; Amachi, Seigo*

sp. DN11 previously isolated from gasoline-contaminated groundwater contained a gene cluster involved in bacterial iodate (IO) respiration. This study determined if strain DN11 performed iodate respiration and assessed its potential use to remove and sequester radioactive iodine (I) from subsurface contaminated aquifers. Strain DN11 grew anaerobically with iodate as the sole electron acceptor. After the growth of strain DN11 on iodate, silver-impregnated zeolite was added to the spent medium to remove iodide from the aqueous phase. In the presence of 200 M iodate as the electron acceptor, more than 98% of iodine was successfully removed from the aqueous phase. These results suggest that strain DN11 is potentially helpful for bioaugmentation of I-contaminated subsurface aquifers.