Efficient novel fungal-enriched biochar formulation for hexavalent chromium bioremediation

• Published in: Journal of environmental management Vol. 370; p. 122806
• Main Authors: Dubey, Priya, Roy, Aditi, Mishra, Sandhya, Naseem, Mariya, Farooqui, Alvina, Patel, Anju, Singh, Poonam C., Srivastava, Pankaj Kumar
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-11-2024
• Subjects: Antioxidants; ChrR enzyme; Hexavalent chromium; Reduction; Sugarcane bagasse biochar (SBC); Hexavalent chromium; Antioxidants; ChrR enzyme; Reduction; Sugarcane bagasse biochar (SBC)
• ISSN: 0301-4797; 1095-8630; 1095-8630
• DOI: 10.1016/j.jenvman.2024.122806

Chromium (Cr), a key element in industrial processes such as leather tanning, poses severe environmental hazards, particularly its hexavalent form, Cr(VI), which is highly toxic and prevalent in tannery effluents/sludge. The persistence and toxicity of Cr(VI) necessitate the development of effective remediation strategies to mitigate its environmental impact. This study investigated the potential of Trichoderma yunnanense (NBRICRF_97) and its combination with 0.5% sugarcane bagasse biochar (SBC) for the reduction of Cr(VI). The results demonstrated that T. yunnanense alone achieved a 91.04% reduction of 50 mg L−1 Cr(VI) within 72 h. Combined with 0.5% SBC, the reduction efficiency increased to 99.65% within 48 h. However, the efficiency decreased at higher concentrations (200 mg L−1). The combination also improved fungal growth and increased extracellular ChrR enzyme activity (13.07 U mg−1 protein compared to the control). Total glutathione activity was boosted by 161.07% at 100 mg L−1 Cr(VI). Antioxidant enzymes (SOD, POD, CAT) and proline mitigated oxidative stress and FTIR analysis revealed changes in fungal cell wall functional groups (-OH and -NH) upon Cr(VI) exposure. SEM-EDX confirmed chromium deposition on fungal surfaces. These results underscore the Cr(VI) detoxification capabilities of T. yunnanense and the synergistic benefits of SBC, suggesting a promising bioremediation strategy for Cr(VI)-contaminated environments. The integration of T. yunnanense with SBC offers a sustainable and cost-effective approach for the bioremediation of Cr(VI)-contaminated sites, with potential for implementation in large-scale environmental cleanup efforts.
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•The study defines a novel fungus (T. yunnanense) for Cr(VI) reduction.•T. yunnanense + 0.5% SBC exhibited remarkable Cr(VI) reduction (99.63%) in 96.•Extracellular ChrR enzyme activity increased (11.17 U mg⁻1) in the presence of SBC.•FTIR, SEM-EDX, and XRD analyses validated Cr(VI) reduction on fungal mycelia.•Reduction kinetics best fit a first-order model.