Synergistic Bioremediation of Pentachloronitrobenzene-Contaminated Soil Via Engineered Fungal-Yeast Fusants and Agricultural Waste Amendments

Abstract

The extensive use of pentachloronitrobenzene (PCNB), a persistent and toxic fungicide, poses severe threats to soil ecosystems. To address this, we developed a synergistic bioremediation strategy combining engineered fungal-yeast fusants and agricultural waste. Protoplast fusion between Pleurotus ostreatus and Saccharomyces cerevisiae yielded a hybrid strain H1-X, which degraded 87.76% PCNB facilitated by Calcium lignosulfonate (Lsa-Ca) in liquid cultures. Through corn stover (CS) amendments and inoculation of H1-X, an unprecedented 83.20% PCNB degradation rate was achieved in non-sterile soil by enriching Proteobacteria (log2FC >6) and Bacteroidota (13%). Metagenomic analysis revealed that CS promoted aromatic compound-degrading taxa and reduced toxic intermediates like pentachloroaniline (metabolism coefficient shifted from −71% to +55%) and hexachlorobenzene (54% reduction). This approach minimized ecological risks by redirecting degradation toward safer products (e.g., chloranilic acid) through synergistic enzymatic activities (nitroreductase, laccase, dehalogenase). Our findings demonstrate a sustainable, cost-effective solution for organic pollutant remediation, leveraging microbial synergy and agricultural waste valorization to restore soil health.

Keywords: Pentachloronitrobenzene, Protoplast fusion, Fungal-yeast fusants, Bioremediation, Corn stover