A method of binding a target metal in solution. The method of binding a target metal comprises contacting a solution containing i) a target metal with ii) an encapsulated exudate of a culture of algal flagellate, or a fraction thereof; or an encapsulated dried Euglena biomass or a fraction thereof, to form a complex between the target metal, and the encapsulated exudate or fraction thereof, or the encapsulated dried Euglena biomass or the fraction thereof; and optionally separating the complex from the solution. The disclosure also relates to a biosorbent element, as well as methods of using same in binding a metal in solution.