Some trace elements enhance biosorption of lead by Rhizopus arrhizus

A high concentration of lead adapted strain of Rhizopus arrhizus was found to be efficient for lead biosorption from culture medium containing 1 mg dm(-3) of lead when the physiological conditions and the chemical composition of the medium were optimized. In the present study, effect of some other trace metals, e.g. iron and manganese, on the biosorption of lead by the microorganism is deciphered when present with lead in the culture medium. It has been found that when iron and manganese in their +2 state are supplemented in the culture medium individually or in combination, biosorption of lead increased from 70.15 to 74.72% in the culture medium containing 1 mg dm(-3) lead. It has also been found that the tolerance of the microorganism towards lead also increased.