Enhancement of heavy metals removal from real electroplating effluent by protoplast fusion technology between different indigenous fungi
摘要
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 Fe3+, Co2+, Ni2+, Pb2+, and Cd2+ (pH 5.0–7.0 at 25–30 °C); Cr6+, and Zn2+ (5.0 -7.0 at 30 °C); Se4+, Ba2+, V+, and Cu2+ (pH 7.0 at 25–30 °C) and As3+ (pH 5.0 at 25–30 °C) from electroplating wastewater. It also reduced the amounts of Hg2+, total dissolved solids, Cl−, SO42−, Na+, and PO4 by 87.90, 77.12, 60.21, 61.05, 62.44, and 71.00%, respectively at pH 7.0 and 30 °C and removed Be2+, Mn2+, K+, chemical oxygen demand, biochemical oxygen demand, total phosphorous, and NO3− 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.