Microbial fuel cells and how cay they produce electricity Lab Report

Microbial fuel cells and how cay they produce electricity - Lab Report Example Microbial fuel cells (MFCs) signify an innovative method of procuring renewable energy in the era of energy crisis. Shewanella oneidensis MR-1 is capable of growing in 50 days in MFCs, the organism is capable of partly oxidizing lactate to acetate with enhanced recovery of the electrons producing electricity. Electricity was generated with lactate or hydrogen on their complete oxidation through electrigens. The cells are attached to the anode, the electrode, thereby conserving energy for growth as the cell is capable of donating its electrons to the electrode. Introduction It is evident that fossil fuels are limited sources for energy on the planet and they are on the verge of exhaustion. Consumption of fossil fuel has augmented climate changes, enhancing temperatures, floods or droughts on the planet causing global warming. Burning involves consumption of oxygen, on flaming fossil fuels which are chiefly carbon, the gas evolved is mainly carbon-di-oxide and obnoxious carbon mono-oxi de. These two gases are hazardous and are chief pollutants. Therefore it is imperative to exploit other means and resources for the production of energy. The new source of energy is retrieved from microbial cells, which are biodegradable and environment friendly (Noam M, 2005). Present era witnesses the generation of electricity from biodegradable compounds, for instance pure chemicals and wastewater. Recently, the production of electricity from microbes paves the way for generating microbial fuel cells capable of producing electricity from complex organic wastes and renewable biomass. Wastes and renewable biomass are attractive sources of energy because both of them encompass natural carbon being fixed in recent times, thus impact on the atmosphere could be reduced. ‘A microbial fuel cells is a mimic of a biological system in which bacteria do not directly transfer their produced electrons to their characteristic electron acceptor’. (Rabaey K, Lissens G, Steven D, Sici liano S and Verstraete W. 2003). MFCs are able to generate electricity through oxidation of organic matter by means of bacteria. Electricity could be generated from a range of biodegradable substrates such as glucose, acetate, ethanol, butyrate, lactate and organic matter. The biggest advantage of MFCs is that they are capable of functioning at room temperature and can be designed to perform numerous functions at different temperatures. In addition, MFCs have also special enzymes to generate electricity. The enzymes produced by MFCs can produce high level of power (Lovely DR, 2006). Enormous factors influence MFCs, these are kind of microbe, type of the proton, resistance and chemical substrate. MFCs also can be coupled with wastewater treatment and thereby exploiting the metabolic potentials of the MFCs, as they are able to metabolize many carbon sources. Chief bacterial population associated with MFCs encompasses Aeromonas, Clostridium, Geobacter, Enterococcus and Shewanella. Ther e are four methods that make the electrons reach the anode they are- (1) Direct membrane associated transfer, (2) Nanowires (conductive pili), (3) Endogenous electron mediators (or electron shuttles) and (4) Exogenous chemical mediators (or electron shuttles). Nanowires plays an important role in the transport of the electrons. Nanowires might help electrons transfer from the bacteria to the metal oxides