Multimetal tolerant fungus Aspergillus flavus CR500 with remarkable stress response, simultaneous multiple metal/loid removal ability and bioremediation potential of wastewater

Abstract

Abstract Microbial bioremediation of multimetal contaminated wastewater can mitigate its environmental toxicity and human health risk. A multimetal tolerating fungus Aspergillus flvaus CR500, able to tolerate As (2000 mg/L), Ni (1600 mg/L), Mn (1600 mg/L), Pb (1200 mg/L), Cr (800 mg/L), Cu (200 mg/L) and Cd (100 mg/L), evident by the tolerance index of 0.22, 0.16, 0.19, 0.09, 0.15, 0.12 and 0.29 respectively A. flavus CR500 adopted multifarious biochemical (enzymatic and non-enzymatic) and morphological strategies (observed by scanning electron microscopic analysis) to deals with As, Pb and Ni toxicity. During the batch study, isolate CR500 could able to remove 99.0, 97.7 and 73.1% of As, Pb and Ni respectively from individual metal contaminated potato dextrose broth (PDB) medium via bioaccumulation and surface adsorption mechanism. A. flavus CR500 also exhibited excellent multimetal (As, Ni, Pb and Cr) removal potential from simulated wastewater (SWW) and Tannery wastewater (TWW) with a high amount of biomass production rate. The removal from 5 mg/L of each metal amended SWW was 97.5, 93.3, 82.2 and 46.6% for As, Pb, Cr and Ni respectively. The toxicity of fungal treated metal solution was reduced, observed from good germination rate and growth of Vigna radiata seeds. Thus A. flavus CR500 has single as well as multimetal removal ability and can be used for ecofriendly treatment of multimetal contaminated wastewater.