Early activated quorum sensing enhanced a nosZ-deficient strain of Pseudomonas aeruginosa for stably recovering nitrous oxide from incineration leachate in microbial electrolysis cell

In this study, a quorum sensing (QS) signal molecule, 3-oxo-C12-HSL, was supplied into delta nosZ Pseudomonas microbial electrolysis cell system for strengthening the N2O recovery from incineration leachate. The resistance for high nitrite loading was strongly improved with nitrite removal efficiency of 80.35% compared to 67.07% from the control on day 13 due to the increasing biomass through early activated QS. Higher N2O proportion in biogas (85.85% on average) was achieved in the QS early activated reactor, which indicated the better potential for N2O recovery. Bacterial community analysis showed the purity of delta nosZ strain with the abundance of 100% in the anode chamber at the end of the operation. This was plausibly related to the increased synthesis of phenazine derivatives by the early activated QS system. These results show a more promising way for N2O recovery by a single engineering bacteria from the high nitrogen contained actual wastewater.

Automated summary

In this study, the recovery of N2O was strengthened in a microbial electrolysis cell system by supplying a quorum sensing signal molecule. The resistance to high nitrite loading was improved and a higher proportion of N2O was achieved through the early activation of the quorum sensing system.