Functional characterization of lignin modifying enzymes produced by white rot fungi for their mycoremediation potential of petroleum (xenobiotic) polluted soil

Abstract

Industrialization has resulted in the introduction of xenobiotics into the environment. These chemicals have polluted soil, water, and air, causing significant health concerns. White rot fungi possess the capability to produce unique enzymes known as ligninmodifying enzymes which can degrade not only lignocellulose, but also many xenobiotics. The aim of the study was to characterize LMEs using various bioassays and to apply the best performing fungi for an attempted bioremediation of a mixture of petroleum products. Using molecular characterization, fungal isolates were identified. These were qualitatively assayed for lignin peroxidase and laccase production. Enzyme production was quantitatively assayed by UV/Vis spectrophotometry using corn husk as growth medium; and common assay reagents were compared. Veratryl alcohol gave the best results for lignin peroxidase while manganese peroxidase activities were similar when using either 2,6 dimethoxyphenol or malonate/Mn3+. ABTS was found to be more sensitive than guaiacol for laccase assay. Trametes hirsuta and Schizophyllum commune were selected as best performing fungi and were used for the attempted remediation PAHs-contaminated soil. Both isolates degraded petroleum fractions, particularly naphthalene by up to 100% and 67.47% respectively. Overall, the study proved the ability of LMEs to degrade xenobiotics.