Isolation of Shewanella spp. from sediments of the Caspian Sea for electricity generation from synthetic wastewater in microbial fuel cells

In recently with the increasing population, industrialization and energy demand, the natural energy resources are being exploited. A microbial fuel cell is a bio-electrochemical system that converts chemical energy in organic compounds to electrical energy through catalytic reactions of microorganisms under anaerobic conditions. Isolation and characterization of Shewanella spp.from sediments of the Caspian Sea and evaluation of its ability to produce electricity from synthetic wastewater were the aims of this study.Samples collected from the sea sediments were cultured in Kligler agar. After incubation at 30 °C, black colonies were selected. After identification of isolates based on morphology, physiology and molecular characteristics, one was chosen and its ability to produce electricity was evaluatedusing microbial fuel cells. Theisolate ME1 was inoculated in LB medium and incubated at 30 ºC for 24 hours. Then the culture was transferred into the anode chamber containing the synthetic wastewater. Neutral red was used as an intermediate electron transport and electrodes were made of graphite. Results showed that the isolate was able to produce electricity with a maximum open circuit voltage of 642 mV. In addition, a maximum power density and a maximum current density was evaluated 58.267 mW/m2 and 254.4 mA/m2, respectively. The COD removal efficiency was 76%. The results of this study demonstrated that the Shewanella ME1 isolated from the sediments had high ability to produce electricity from synthetic wastewater in microbial fuel cells

Keywords:

Microbial fuel cell , Shewanella , Synthetic wastewater , Produce electricity