Biosorption of cadmium by the fungi Aspergillus niger and Penicillium citrinum isolated from the soil in FCVC Power Plant, Cabanatuan City, Nueva Ecija, Philippines

Abstract

The use of fungi in the removal of heavy metals through biosorption is a field yet to be ventured in the Philippines. In this study, of the several fungal isolates obtained from the soil in the vicinity of a power plant in Nueva Ecija, two fungal isolates were selected on the basis of their ability to grow on cadmium-infused agar of varying cadmium concentrations (i.e. 50, 100, 150, 200, and 250 ppm). After 14 days, the fungi were separated from the solid media and were analyzed for cadmium bound on the cell wall by Flame Atomic Absorption Spectrophotometry (FAAS). The two fungi isolated from the soil in Nueva Ecija were identified to be Aspergillus niger and Penicillium citrinum. Biosorption profile of the two fungal soil isolates showed that P. citrinum significantly adsorbed cadmium (22 ppm) onto its cell wall compared to A. niger (4 ppm). This study also showed that as the concentration of the cadmium increased in the solid media, more cadmium was bound onto the cell wall of P. citrinum. It can then be inferred that Penicillium citrinum is more adept at adsorbing cadmium than Aspergillus niger based on the results of the FAAS testing