Mechanism of Phanerochaete chrysosporium-mediated tetracycline hydrochloride removal promoted by low-dose silver nanoparticles

Abstract

The influence of silver nanoparticles (AgNPs) on environmental microorganisms has been extensively reported, however, there is currently limited understanding of effects of stress-induced by AgNPs on other pollutant degradation. In this study, Phanerochaete chrysosporium was stimulated by different concentrations of AgNPs to explore its effect on P. chrysosporium-mediated degradation of tetracycline hydrochloride (TCH). The results indicate that treatment with AgNPs at low concentration resulted in a considerable increase in TCH degradation, TCH degradation reached a maximum of 97% with 0.1 mg L−1 AgNPs treated after 3 d, and the viability of P. chrysosporium increased 1.48 times compared with the control group. The largest O2 influx of − 17 pmol cm−2 s−1 under 0.1 mg L−1 AgNPs treatment reveal the enhancement of P. chrysosporium respiration. In addition, low concentrations of AgNPs could induce the overexpression of cytochrome P450 and extracellular degradation enzymes MnP-related genes in stimulated cells, which further induce the production of extracellular degrading enzymes (51.0 U L−1 MnP and 23.7 U L−1 LiP) to accelerate the degradation of TCH. Together, our combined results uncovered the enhanced degradation mechanisms of P. chrysosporium induced by which AgNPs under sublethal dosage.