Efficient catalytic degradation and detoxification of 6PPD-quinone by the multifunctional enzyme system of phanerochaete chrysosporium.

The widespread environmental presence and toxicity of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-quinone, 6PPD-q), a rubber-derived pollutant, necessitates effective degradation strategies. This study demonstrates for the first time that Phanerochaete chrysosporium (P. chrysosporium) achieves a 99.06 % removal rate of 6PPD-q within 7 days through adsorption combined with enzyme catalysis. The breakdown of the quinone structure, primarily driven by lignin peroxidase isoenzymes, is accompanied by carbon chain shortening and structural simplification, which enhance the bioavailability of degradation products. These metabolites are assimilated and further mineralized by the P. chrysosporium metabolic system. Comprehensive toxicity assessments using zebrafish and Escherichia coli confirmed the biosafety of all degradation products. This study provides mechanistic insights into the fungal degradation of 6PPD-q and presents a sustainable approach for mitigating the environmental risks posed by other pollutants. Furthermore, a new generation of innovative bioremediation technologies can be developed by engineering fungi to regulate extracellular electric potential and enhance catalytic enzyme activity.