Based on the catalytic properties of electrochemically active 
organisms, activated-sludge based-microbial fuel cell (MFC) system was 
designed for the electricity generation. As a microbial energy source, 
glucose has been exploited as electron provider. During the incubation 
time of bacterial culture in a mediated-less MFC, the cell voltage and 
degradation rates of glucose were determined. The results showed that 
electricity output was increasing due to the increase of glucose 
concentration. The MFC displayed a maximum power density of 52 
mW/m2
at stable current density 275 mA/m2
and a maximum glucose 
degradation rate 94.4%. However, the electrical current was dropped 
when the glucose level in the bacterial culture was higher than 5.0 g/l. 
This fact was confirmed by studying the glucose concentrations using 
cyclic voltammetry.Concerning to the extracellular electron transfer 
mechanism(s), the biofilm formation on the anode was visible by 
Scanning electron Microscope (SEM). SEM showed the intensive 
adherence of microbes on anodic electrodes.On the other hand, rates of 
glucose consumption (degradation) were analyzed, the degradation rate 
was in accordance with the electrical current.Therefore, the current study 
demonstrates the applicable use of activated sludge-based microbial fuel 
cells for bioelectricity generation.