Bacillus megaterium МК64-1 as a Bioagent in a Microbial Fuel Cell

Abstract

Alternative energy and the disposal of pollutants are important areas of development in the field of applied ecology. Microbial fuel cell technology uses pollutants as substrates with a negative energy cost. The electrochemical characteristics of microbial fuel cells (current strength, voltage, power density) were studied to assess the prospects for using Bacillus megaterium MK64-1 (the strain was deposited with VKPM under registration number B-7998) as a bioagent in them. Two nutrient media were used in the experiment – synthetic wastewater and Ashby medium. The volume of the anode chamber of the involved microbial fuel cells is 120 ml, the volume of the cathode chamber is 150 ml. The experiment was set up under aseptic conditions. The total microbial count of the working solution was 4×105 CFU/ml. The experiment included three biological and three analytical replicates. The duration of monitoring the dynamics of fuel cell performance was twelve days. Stabilization of the output voltage was recorded on the fourth day of the experiment. In Ashby medium, starting from the seventh day, electrical indicators continued to grow. The value of external resistance is revealed, at which the highest value of the MFC power is observed - 1 kΩ. The maximum value of the specific power of individual MFC was noted at the level of 14.1 mW/m² in Ashby medium and 13.2 mW/m² in synthetic wastewater. The difference in the composition of nutrient media did not have a significant effect on the dynamics of electrochemical parameters. It is concluded that the studied strain is promising for use in biological fuel cells.

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Identifiers

DOI

10.26516/2073-3372.2022.40.66

Journal

The Bulletin of Irkutsk State University. Series Biology. Ecology

Year

2022