Investigating wettability alteration during MEOR process, a micro/macro scale analysis

► Enterobacter cloacae strain change the wettability of neutral and oil wet surfaces. ► Microbial products do not change the wettability significantly. ► Presence of bacterial cells is essential for wettability alteration. ► Biofilm formation is considered to be the main mechanism of the wettability alteration. ► Bacteria show the potential to remove asphaltene compounds from the glass surface.