Bacterial community structure and enzyme activities in a membrane bioreactor (MBR) using pure oxygen as an aeration source

► Enzyme activities in pure O2-aerated MBR are similar to those reported under conventional aeration. ► Temperature and volatile suspended solids significantly influence enzyme activities in the MBR. ► The bacterial community is versatile and can answer in a flexible way to environmental changes. ► The MBR community was functionality equivalent to those developed under conventional aeration.