Lipid production and heavy metals adsorption by an Aspergillus fumigatus GAH1 isolate

Few species of filamentous fungi can accumulate considerable amounts of intracellular lipids when grown under certain stress conditions; thus, they can be used for biodiesel production. Moreover, their residual biomass can be used for the removal of heavy metals from contaminated water. An oleaginous Aspergillus fumigatus GAH1 isolate was isolated from a soil sample in Borg El-Arab industrial area, Alexandria, Egypt, and was characterized in batch cultures. The influence of different carbon and nitrogen sources and the initial pH of the medium on the fungal biomass and lipid production was investigated. Under optimized conditions, the A. fumigatus GAH1 isolate could accumulate up to 22.4% of its dry biomass as lipids. Oleic and palmitic acids were the dominant fatty acid fractions produced. After lipid extraction, to further improve the process economy, the fungal biomass was applied as a biosorbent to remove heavy metals such as Cr, Cd, and Zn from contaminated wastewater. The biosorption efficiency and capacity of the raw, H2O-washed, and NaOH-treated fungal biomass were examined. The biosorption capacity of 33.37, 29.29, and 27.75 mg/g was recorded for Cr, Cd, and Zn, respectively. Moreover, the biosorption efficiency was more than 69% for the tested heavy metals. In conclusion, A. fumigatus GAH1 may be considered as a promising biodiesel producer, and its biomass waste can be further used for the biosorption of heavy metals from contaminated wastewater.