Construction and characterization of nitrate and nitrite respiring Pseudomonas putida KT2440 strains for anoxic biotechnical applications

► Two Pseudomonas aeruginosa cosmids containing gene clusters for nitrate or nitrite respiration were isolated. ► Transfer of these cosmids in the obligate aerobic Pseudomonas putida KT2440 generated two strains, which anaerobically reduced nitrate and nitrite, respectively. ► Microarray analysis confirmed expression of all structural, maturation and regulatory P. aeruginosa denitrification genes. ► Recombinantly produced P. aeruginosa enzyme systems allowed for anaerobic life of P. putida KT2440. ► Expression of P. putida genes encoding a putative copper stress response operon was observed.