Potential of arsenic bioremediation by a cyanobacterium isolated from the Salado River in the Atacama Desert

Abstract

Cyanobacteria and microalgae are recognized as excellent metal(loid)s-bioremediators of aquatic systems. We isolated a cyanobacterium from the Salado River in the Atacama Desert, northern Chile, which was identified as Cyanobium sp. Growth inhibition bioassays were conducted with arsenic and cadmium, and tolerance of Cyanobium to these metals was estimated. Removal of arsenic was assessed under different pH conditions and over time. We showed that the Cyanobium strain isolated from the Salado River has a greater tolerance to the arsenic and cadmium compounds than other species commonly used in metal(loid)s-bioremediation. Removal of up to 90% of arsenic was obtained in alkaline conditions, within the first 3 hours of exposure suggesting that Cyanobium sp. isolated from the Atacama Desert could be further studied with biotechnological purposes and to understand the evolutionary mechanisms of adaption to arid environments.