Updated project metadata. The physiological adaptations of the WWTP isolate T. elongata str. LP2 during an oxic/anoxic shift experiment were analyzed by HRMS-proteomics. E. coli was used as reference organism as it shares several metabolic capabilities and is regularly introduced to wastewater treatment plants, but without succeeding there. In contrast to E. coli, T. elongata was able to steadily grow and did not need to activate additional metabolic pathways for anaerobic energy harvest. At the same time, given substrates were exploited far more efficient than by E. coli. Based on the acquired data, we hypothesize that T. elongata shows high metabolic robustness when encountering the WWTP which enables continuous growth to successfully compete in this environment.