Journal of Microbial & Biochemical Technology

Abstract

Molecular Identification and Nickel Biosorption with the Dead Biomass of Some Metal Tolerant Fungi

Nourah Hassan Alzahrani, Khadijah Hussain Alamoudi and Mervat Morsy Abbas Ahmed El-Gendy

Nickel as a heavy metal is the fifth most abundant element on earth. It has many applications and usages. The present study was conducted to isolate metal tolerant fungal strains, molecular identification and evaluating the bioprocess efficiency by assessment the effect of some environmental conditions on biosorption capacity by the dead biomass of the selected fungi. Twelve fungal isolates obtained from polluted water of the nickel (Ni²⁺) were screened, fungi under the isolation number MERV21569 and AHM21696 proved to be the best biosorbents. They removed Ni²⁺ by 79.6% and 85.2% with uptake equal 4.33 and 4.75 μg/mL, respectively. According to the molecular identification of these selected isolates, they were designated as Aspergillus sojae MERV21569 and Aspergillus terrus AHM21696. It was found that the sorption isotherms for Ni²⁺ by both fungi appeared well acceptable with both Freundlich and Langmuir's models. Both isolates were investigated and evaluated with different bioprocess factors including, initial concentrations of Ni²⁺, different contact times and different initial pH of Ni²⁺ solution with different process times. Metal resistant capacity of the selected fungi against ten heavy metals including Cd²⁺, Pb²⁺, Cu²⁺, Hg²⁺, Ag⁺, Cr⁶⁺, Ni²⁺, Zn²⁺, Fe³⁺ and Al³⁺, which are represent the highly poisonous heavy metals in wastewaters of different industries was determined. In waters polluted with heavy metals the maximum removal of Ni²⁺ (100% for both strains) was achieved within 4 and 2 h contact time by using the dead biomass of Aspergillus sojae MERV21569 and Aspergillus terrus AHM21696, respectively.