NOVEL METHOD OF MICROBIAL ELECTROPOTENTIAL GENERATION USING MAGNETOTACTIC BACTERIA

Abstract

A completely new method is introduced for production of electricity using special type of microbial culture known as Magnetotactic bacteria. Magnetotactic bacteria have a unique property of intracellular magnetite crystal formation, aligned in a line to form a chain. This chain of tiny bacterial magnetite crystals is known as magnetosome which produces a permanent magnetic field in nearby region of the cell. In context to electricity production, this magnetic energy associated with these magnetomicrocreatures can be utilized along with some physical laws of electromagnetic induction to make an electropotential generation system. A wild type of aerobic strain of Magnetotactic bacteria (MTB) was successfully isolated in modified nutrient medium. Ferric quinate was used as the main iron source. Magnetic behavior of the bacterial cells was observed during macroscopic and microscopic analysis. Motility towards the externally applied magnetic field direction confirmed the isolated strain to be magnetotactic in nature. Scanning electron microscopic analysis was used to study the morphology, which shows rod like shape of isolated bacteria. Electron dispersive X ray diffraction analysis confirmed the presence of elemental carbon as a major constituent. Moreover, elemental iron and oxygen indicated the formation of magnetic material inside the bacterial cells. Vibrating Sample Magnetometer analysis was performed to reveal the magnetic characteristics of the isolated bacterial strain. Reactor unit consisted of (1) MTB culture; (2) copper coil and (3) hollow compartment. The MTB interacted with copper coil in such a way that there was no direct contact of MTB and coil system. This resulted into electropotential generation in the copper coil. The potential difference at the two free ends of the copper wire was measured using thermocouple signal processing device. The reactor produced voltage in the range of microvolt. Effect of compartment height variation was studied. It signifies the variation in culture volume and number of coil turns. Several modifications were done in the designed unit and performance of both the designs was compared.