Bacterial metabolism of discotic liquid core component-triphenylene; a future xenobiotic

Triphenylene and its derivatives are gaining significant importance due to their role in the production of purely organic columnar discotic liquid crystals, which are used in organic light-emitting diode (OLED) screens and semiconductors. In the current study, Paenibacillus sp. PRNK-6 was evaluated for its ability to degrade the tetracyclic aromatic hydrocarbon, triphenylene. Paenibacillus sp. PRNK-6 is a promising PAH-degrading bacterium that utilizes triphenylene as its sole source of carbon and energy. Within 120 h of incubation, PRNK-6 degraded 89.75% of 100 mgL⁻¹ triphenylene. Metabolite analysis, enzyme assays, and metabolite feeding experiments indicated that triphenylene was completely metabolized without forming any dead-end products. Several triphenylene metabolites were identified, and a metabolic map of triphenylene was constructed based on the characterization of metabolites, and the specific activities of enzymes involved in its degradation.