Characterization of the Coriolopsis gallica DyP for Its Potential to Biotransform Various Fluoroquinolones

<i>Coriolopsis gallica</i> (<i>Cga</i>) is a white-rot fungus renowned for its ability to secrete ligninolytic enzymes that are capable of oxidizing phenolic compounds. This study aimed to investigate the biochemical characteristics of a dye-decolorizing peroxidase named <i>CgaDyP1</i> and test its ability to biotransform antibiotics. <i>CgaDyP1</i> was cloned and heterologously expressed in <i>Escherichia coli.</i> We fully characterized the biochemical properties of <i>CgaDyP1</i> and evaluated its dye-decolorizing potential to confirm that it belongs to the DyP class of enzymes. We also tested its fluoroquinolone antibiotic biotransformation potential for possible biotechnological applications. Alignment of the primary amino acid sequence with DyP homolog sequences showed that <i>Cga</i>DyP1 has high similarity with other fungal DyPs. The recombinant <i>Cga</i>DyP1 exhibited activity on substrates such as ABTS and 2,6-dimethoxyphenol (DMP) with optimal performance at a pH of 3, although activity at pH 2.5, pH 4, and pH5 diminished over time. Thermostability tests indicated that the enzyme remains stable at temperatures between 30 °C and 50 °C and retains 70% of its initial activity after 180 min at 50 °C. Tests on the effect of hydrogen peroxide on <i>CgaDyP1</i> activity found peak activity at 0.25 mM H₂O₂. <i>Cga</i>DyP1 decolorized five industrial dyes, and kinetics data confirmed that it belongs to the DyP class of enzymes. <i>Cga</i>DyP1 was shown to biotransform some of the 7 recalcitrant fluoroquinolone antibiotics tested here, including levofloxacin, moxifloxacin, and norfloxacin, and thus holds potential for biotechnological applications.