Optimization of Chromium and Copper Ions Uptake by Aspergillus Terreus Strain Using Different Techniques

Abstract

The heavy metal resistant isolate FR1 was identified using phenotypic and genotypic characteristics; it was classified as Aspergillus terreus strain. Lactose and yeast extract were favorable for Cr+5 and Cu+2 ions biosorption by tested strain after 6 days incubation period. The positive significant variables (yeast extract, temperature & inoculum size or lactose, yeast extract, temperature & incubation period) affecting heavy metals biosorption using Placket-Burman statistical experimental design in presence Cr+5 and Cu+2 were further optimized by using response surface methodology. It was found that the highest growth of strain in presence of Cr+5 and Cu+2 (4.31 and 3.69 gL-1) were attained at 0.15% yeast extract, 2% inoculum size & incubated at 28°C and 0.65 % lactose, 0.15% yeast extract, an incubation temperature of 30 °C and 8 days incubation period, respectively. There is no significant difference between absorption and adsorption mechanism for reduction of heavy metals from Egyptian phosphatic fertilizer sample.