Adaptive responses of IEGM 1277 to the action of meloxicam and its efficient biodegradation.

Introduction: Pharmaceutical contaminants such as meloxicam pose significant environmental risks due to their persistence and toxicity. The biodegradation potential of actinomycetes, particularly representatives of , offers promising avenues for eco-friendly wastewater treatment. However, the ability of to fully degrade meloxicam has not been previously demonstrated.

Methods: The biodegradation of meloxicam was investigated using IEGM 1277 as a model organism. Metabolite identification was performed using liquid chromatography-mass spectrometry (LC-MS). Candidate genes encoding meloxicam-oxidising enzymes were identified via genomic analysis. Adaptive bacterial responses to meloxicam exposure were characterised using atomic force microscopy (AFM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX).

Results: IEGM 1277 successfully decomposed meloxicam into primary metabolites, 5'-hydroxymethyl- and 5'-carboxymeloxicam, which exhibited reduced (eco)toxicity compared to the parent compound. Genomic analysis revealed several candidate genes potentially involved in meloxicam oxidation. Microscopic and spectroscopic analyses demonstrated significant phenotypic and metabolic changes in bacterial cells, indicating adaptive defence mechanisms triggered by meloxicam exposure.

Discussion: This study provides the first evidence of complete meloxicam biodegradation by and elucidates the underlying enzymatic and adaptive cellular responses. The findings highlight the potential application of IEGM 1277 in developing efficient and environmentally safe biotechnologies for pharmaceutical wastewater treatment.