Jeonbuk National University (JBNU) PhD candidate Kwangmin Lee (Graduate School, Department of Integrative Environmental Biotechnology; supervisor Professor Oh Byung-taek) has succeeded in screening a microbial strain capable of simultaneously removing the persistent chemicals deltamethrin and dibutyl phthalate (DBP), attracting attention from the academic community.

This achievement was presented at the recent Korean Society for Microbiology International Conference (MSK2025) and received the Outstanding Poster Presentation Award, suggesting the potential for advances in biological remediation technologies for mixed-contamination environments.

The study is significant because, although the two substances are used concurrently in agricultural and industrial settings and are detected together in soil and water systems, biological treatment technologies capable of degrading both substances simultaneously in mixed-contamination environments are very limited worldwide.

Deltamethrin is subject to regulation due to its high environmental persistence and ecotoxicity, and DBP is classified as a hazardous substance that causes endocrine disruption and reproductive toxicity, leading to strengthened management measures.

The research team secured a strain capable of growth under high-concentration mixed-contamination conditions (200 mg/L each) through Minimum Inhibitory Concentration (MIC) assessment and degradation efficiency analysis. In particular, under 100 mg/L conditions the strain achieved removal rates of 49.14% for deltamethrin and 56.72% for DBP, demonstrating the practical potential of single-strain simultaneous treatment of mixed contaminants.

PhD candidate Kwangmin Lee emphasized, “Existing physical and chemical treatment methods have drawbacks such as secondary pollution and high costs. The strain obtained in this study showed stable degradation capabilities even in mixed-contamination scenarios, making it an important starting point for the development of eco-friendly biological remediation technologies.”

He added, “The microbial degradation research infrastructure established by Professor Oh Byung-taek provided the foundation for this study. Going forward, we will advance the technology through elucidation of metabolic pathways, toxicity assessment of metabolites, and optimization of conditions.”

Supervisor Professor Oh Byung-taek is an expert who has led national and international research in microbial remediation of persistent environmental pollutants. In particular, mixed-contamination issues have been designated as priority management areas by the Ministry of Environment and international environmental organizations. The current research findings are expected to serve as baseline data for national environmental policy formulation and the industrialization of eco-friendly remediation technologies.

Meanwhile, the research team is currently conducting mass spectrometry (MS)-based metabolite analysis, ecotoxicity assessment, and pilot-scale demonstration tests simulating actual contaminated soil and water systems. These efforts are expected to lead to the development of field-applicable remediation technologies based on bioaugmentation and biostimulation.