A biosorbent for removing cationic and/or anionic metals from aqueous solutions, and a process for the production of the biosorbent. The biosorbent includes bacterial aggregates of Bacillus sp. VCHB-10, deposited as NRRL-B-30881, and treated with polyethyleneimine and glutaraldehyde. Among the metals in their cationic form, the following are considered: cations of Ag, Al, Au, Co, Cd, Cu, Cr, Fe, Hg, Mn, Ni, Pb, Pd, Pt, U, Th and Zn. Among the metals in their anionic form, the following are considered: anions of As, Cr and Mo. Removal or recovery of metals from wastewater using the biosorbent is also described.