<p><i>Pseudomonas aeruginosa</i> has been reported to degrade C1 and inorganic nitrogen compounds through multiple metabolic pathways. This study aims to shed light on the uncharted CH₄ and NH₄ oxidation pathways in <i>P. aeruginosa</i> strain AAK/M5 for utilization of C1 and N1 compounds in syntrophic nitrifying denitrifying medium. Around 9% and 11% higher NH₄⁺–N and NO₃^––N removal respectively was observed in presence of CH₄ as carbon source. Similarly, CH₄ removal was 3.6-fold higher in the set supplemented with NO₃^–-N as nitrogen source than the set with NH₄⁺-N. Intermediates of methane oxidation viz., CH₃OH, HCOOH, and that of nitrate reduction viz., NO₂^––N were also detected. Induction of methane/ammonia monooxygenase in presence of CuSO₄ revealed highest NH₄⁺–N removal (84.89&#xa0;mg/L) and CH₄ removal (30%) at 10 µM CuSO₄. Degradation kinetics using high density resting bacterial cells in phosphate buffer resulted in <i>µ</i>_max (min^− 1) of 0.0018, 0.0049, 0.0034, 0.0038, and 0.0012, for NH₄⁺–N, NH₂⁺–N, NO₃^––N, NO₂^––N and CH₃OH respectively. Additionally, affirmation of CH₄/NH₃ oxidizing enzyme was done via <i>in silico</i> analysis which revealed the presence of two enzymes sharing 38.3% and 31.4% homology with ammonia monooxygenase subunit C and soluble methane monooxygenase subunit C, respectively. Furthermore, a quinoprotein methanol dehydrogenase was detected in the genome. The results thus suggested the CH₄ metabolizing capacity of <i>P. aeruginosa</i> AAK/M5 in presence of ammonical/nitrate nitrogen by virtue of key enzymes sharing homology with ammonia monooxygenase and soluble methane monooxygenase.</p>