In recent years, microbial fuel cells (MFC) have drawn attention as a solution to energy problems. MFC is a device that produces electric power by harvesting electrons generated on an electrode when a microorganism decomposes an organic substance. In addition, by using organic substance in wastewater as a nutrient source for microorganisms, MFC can simultaneously perform wastewater treatment and electricity production. However, the effective use of anode solution of MFC has never been studied, and we tried to produce useful materials using MFC. Among the microorganisms that produce useful substances such as enzymes, plant hormones and antibiotic substances, we focused on Bacillus subtilis RB14, which produces antifungal substance iturinA. B. subtilis RB14 forms thick biofilm, and the clear relationship between biofilm formation and antifungal substance production was observed. When the B. subtilis RB14 was put into the autoclavable MFC, electricity and antibiotic production by B. subtilis RB14 has been observed. Although, antifungal substance was produced after the 2nd day of culture, increase of the voltage was observed around the 9th day, and then the voltage was continuing to increase until about 170 mV. This seems to be the first experiment that electricity generation and antibiotic production were done by MFC. In order to investigate the application of the anodic solution containing antifungal substances produced by B. subtilis RB14. The solution was sterilized by filtration and, the solution showed clear suppressive effect against plant pathogen Rhizoctonia solani K1, which infects a lot of plant species and causes many diseases including damping off. The results suggest that anode solution of MFC can be used for agriculture application to make suppressive soil, which can suppress plant pathogens. Plant experiments with inhibitory effects of anode solution on plant pathogens in soil and optimization of culture conditions for the antibiotic production and electricity generation using B. subtilis RB14 and other useful microbes are now in progress.

Effective application of anode solution in microbial fuel cell to agriculture

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.