Synthesis of copper oxide nanoparticles using capsular polymeric substances produced by Bacillus altitudinis and investigation of its efficacy to kill pathogenic Pseudomonas aeruginosa

•CPS was extracted from a marine Bacillus altitudinis SORB11.•Mannose, glucose, and galactose were the major constituents of sugar residues along with sulfur.•Crude CPS was used as a coating and stabilizing agent for the synthesis of CuO NPs.•⁓5 mcg/ml CuO NPs suspension exhibited effective antimicrobial activity against pathogenic Pseudomonas aeruginosa.