Optimization of Aspergillus niger Nutritional Conditions using Statistical Experimental Methods for Bio-Recovery of Manganese from Pyrolusite

Abstract

The nutritional requirements for Aspergillus niger PCSIR-06 for bio-recovery of manganese from pyrolusite ore were optimized. Box-Bhenken design and response surface methodology were used for designing of experiment and statistical analysis of the results. This procedure limited the number of actual experiments to 54 for studying the possible interaction between six nutrients. The optimum concentration of the nutrients were Sucrose 148.5 g/L, KH2PO4 0.50 g/L, NH4NO3 0.33 g/L, MgSO4 0.41 g/L, Zn 23.76 mg/L, Fe 0.18 mg/L for Aspergillus niger to achieve maximum bio-recovery of manganese (82.47 ± 5.67%). The verification run confirmed the predicted optimized concentration of all the six ingredients for maximum bioleaching of manganese and successfully confirmed the use of Box-Bhenken experimental design for maximum bio- recovery. Results also revealed that small and less time consuming experimental designs could be efficient for optimization of bio-recovery processes.