Synergistic lignin degradation between Phanerochaete chrysosporium and Fenton chemistry is mediated through iron cycling and ligninolytic enzyme induction.

被引：8

作者：

van der Made J.J.A. ^{[1
]}

Landis E.A. ^{[1
]}

Deans G.T. ^{[1
]}

Lai R.A. ^{[1
,2
]}

Chandran K. ^{[1
]}

机构：

[1] Department of Earth and Environmental Engineering, Columbia University, New York, NY

[2] Department of Civil and Environmental Engineering, Stanford University, Palo Alto, CA

来源：

Science of the Total Environment | 2023年 / 905卷

关键词：

Fenton; Iron redox cycling; Lignin; Ligninolytic enzymes; Phanerochaete chrysosporium; White rot;

D O I：

10.1016/j.scitotenv.2023.166767

中图分类号：

学科分类号：

摘要：

Removal of recalcitrant lignin from wastewater remains a critical bottleneck in multiple aspects relating to microbial carbon cycling ranging from incomplete treatment of biosolids during wastewater treatment to limited conversion of biomass feedstock to biofuels. Based on previous studies showing that the white rot fungus Phanerochaete chrysosporium and Fenton chemistry synergistically degrade lignin, we sought to determine optimum levels of Fenton addition and the mechanisms underlying this synergy. We tested the extent of degradation of lignin under different ratios of Fenton reagents and found that relatively low levels of H2O2 and Fe(II) enhanced fungal lignin degradation, achieving 80.4 ± 1.61 % lignin degradation at 1.5 mM H2O2 and 0.3 mM Fe(II). Using a combination of whole-transcriptome sequencing and iron speciation assays, we determined that at these concentrations, Fenton chemistry induced the upregulation of 80 differentially expressed genes in P. ch including several oxidative enzymes. This study underlines the importance of non-canonical, auxiliary lignin-degrading pathways in the synergy between white rot fungi and Fenton chemistry in lignin degradation. We also found that, relative to the abiotic control, P. ch. increases the availability of Fe(II) for the production of hydroxyl radicals in the Fenton reaction by recycling Fe(III) (p < 0.001), decreasing the Fe(II) inputs necessary for lignin degradation via the Fenton reaction. © 2023 The Authors

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