Screening and selection of autochthonous fungi from leachate contaminated-soil for bioremediation of different types of leachate

Abstract

This study aims to use contaminated soil with leachate to select autochthonous fungi that are able to bioremediate three types of leachate, (Young (YL), Intermediate (IL) and Old (OL)). Eleven fungal species were isolated via the enrichment method using the leachate as the sole source of carbon and energy. The isolates were evaluated for their ability to grow and remove organic pollutants at 100%, 50% and 25% (v/v) of leachate in both solid and liquid cultures that were spiked with malt extract. The results indicated that only three fungi, <i>Aspergillus flavus</i> (<i>A. flavus</i>-LC106118), <i>Aspergillus niger</i> (<i>A. niger</i>-KT192262) and <i>Fusarium solani</i> (<i>F. solani</i>-KX349467) showed significantly high capacity to grow on leachate, with maximum radial growth rates (Gr) of 7.5 mm, 4.7 mm , and 5.3 mm, respectively. In addition, 34%, 22%, and 27%, respectively of COD removal rates were obtained at 25% concentration in YL. A. flavus was the most tolerant fungus against landfill leachate, followed by <i>F. solani</i>, and finally <i>A. niger</i>. Therefore, these three fungi are good candidates for leachate bioremediation. However, for a better remediation, the combined effects of different types of fungi and leachates on the fungal growth need to be considered during the fungi selection.