Enhancement of heavy metals removal from real electroplating effluent by protoplast fusion technology between different indigenous fungi

Abstract Among a collection of 64 natural isolates derived from the mycobiome of electroplating effluents screened for heavy metals biosorption, two fungal isolates AHM 21 and AHM 53 identified and designated as Fusarium sp. AHM 21 and Alternaria sp. AHM 53 proved to be potent fungal biosorbents for efficient removal of heavy metals. They were used as parental strains in intergeneric protoplast fusion technique. One of fifteen fusants; recombinant strain RAM 5 showed improved biosorption activity against a wide range of heavy metals compared to its parental strains. The recombinant strain RAM 5 achieved 100% removal of Fe 3+ , Co 2+ , Ni 2+ , Pb 2+ , and Cd 2+ (pH 5.0–7.0 at 25–30 °C); Cr 6+ , and Zn 2+ (5.0 -7.0 at 30 °C); Se 4+ , Ba 2+ , V + , and Cu 2+ (pH 7.0 at 25–30 °C) and As 3+ (pH 5.0 at 25–30 °C) from electroplating wastewater. It also reduced the amounts of Hg 2+ , total dissolved solids, Cl − , SO 4 2− , Na + , and PO 4 by 87.90, 77.12, 60.21, 61.05, 62.44, and 71.00%, respectively at pH 7.0 and 30 °C and removed Be 2+ , Mn 2+ , K + , chemical oxygen demand, biochemical oxygen demand, total phosphorous, and NO 3 − by 96.14, 99.33, 71.00, 82.14, 67.71, 94.50, and 58.43% (pH 5.0 at 25 °C). Interestingly, fusant RAM 5 showed no antiproliferative activity against hepatocellular carcinoma, human breast cancer and normal human skin fibroblast cell lines. The current work provides cheaper, nontoxic, and more environmentally friendly biological treatment based on fungi for metals removal.