Selenium biomineralization for biotechnological applications

• Biomineralization enables recovery of the scarce element selenium as Se0 and metal selenides.
• An integrated treatment strategy is needed to achieve the selenium discharge limit <5 μg l–1.
• Polluted waters are a potential selenium resource for recovery.
• Selenium has a multitude of functions in health, environment, and nanotechnology.

Selenium (Se) is not only a strategic element in high-tech electronics and an essential trace element in living organisms, but also a potential toxin with low threshold concentrations. Environmental biotechnological applications using bacterial biomineralization have the potential not only to remove selenium from contaminated waters, but also to sequester it in a reusable form. Selenium biomineralization has been observed in phylogenetically diverse microorganisms isolated from pristine and contaminated environments, yet it is one of the most poorly understood biogeochemical processes. Microbial respiration of selenium is unique because the microbial cells are presented with both soluble (SeO42– and SeO32–) and insoluble (Se0) forms of selenium as terminal electron acceptor. Here, we highlight selenium biomineralization and the potential biotechnological uses for it in bioremediation and wastewater treatment.