Arsenic biomethylation by photosynthetic organisms

Arsenic (As) is a ubiquitous element that is widespread in<br />the environment and causes numerous health problems.<br />Biomethylation of As has implications for its mobility and<br />toxicity. Photosynthetic organisms may play a significant<br />role in As geochemical cycling by methylating it to different<br />As species, but little is known about the mechanisms<br />of methylation. Methylated As species have been found in<br />many photosynthetic organisms, and several arsenite<br />S-adenosylmethionine (SAM) methyltransferases have<br />been characterized in cyanobacteria and algae. However,<br />higher plants may not have the ability to methylate As.<br />Instead, methylated arsenicals in plants probably originate<br />from microorganisms in soils and the rhizosphere.<br />Here, we propose possible approaches for developing<br />&lsquo;smart&rsquo; photosynthetic organisms with an enhanced<br />and sensitive biomethylation capacity for bioremediation<br />and safer food