Influence of metals on lignocellulolytic enzyme production and metal removal by Phlebia brevispora in a wheat straw based fixed-bed bioreactor

Abstract

Heavy metals contamination poses a significant environmental threat, which requires the development of eco-friendly bioremediation techniques. Present research work was conducted using wheat straw in submerged conditions for the growth of white rot fungus, Phlebia brevispora in the presence of varying concentrations of Cd, Pb, Ni, and Cr. The lignocellulolytic enzyme production ability of fungus was monitored. A wheat straw-based fixed-bed bioreactor was designed to treat metal-containing water in continuous mode. The fungus showed a positive influence on laccase production, cellulase production, and lignin peroxidase activity. As observed through atomic absorption spectroscopy (AAS), Cr removal efficiency was 78%–80%, regardless of the initial metal concentration. The Cr was also found on the surface of fungal mycelium as per the results obtained from SEM–EDX. The continuous bioreactor achieved 98%–99% metal removal, making it a natural and cost-effective solution for metal removal from wastewater using P. brevispora.