Question

MICROBIOLOGY

On example of a consortial arrangement might involve the use of complementary electron donors and acceptors to create a cyclic turnover of a compound. Draw an example of a cycle of this type, and explain where the energy and carbon inputs to the system are, as well as what role the cycled nutrient plays in each member of the consortium.

Answer 1

An example of microbial consortium can be microbial fuel cell.

Microbial Fuel Cells (MFCs) are among the most prominent biological systems for energy production. The possibility of using microorganisms to generate electricity in fuel cells is based on the biochemical processes of energy production. Microorganisms degrade organic compounds by removing electrons from these compounds (oxidation) and releasing them to a final receptor, such as oxygen. However, even in the absence of oxygen, certain bacteria can transfer electrons from organic compound oxidation to systems outside the cell.

MFCs usually consist of two compartments separated by a membrane that prevents oxygen diffusion to the anode and enables the resulting protons to reach the cathode. An external circuit connects the two electrodes, allowing for electron transfer and use of the energy generated. In the anode compartment, a graphite cloth collects the electrons produced by the anaerobic microorganisms during substrate oxidation. In the aerobic cathode compartment, the electrons generated reduce oxygen and, together with protons, produce water.

The energy and carbon inputs are obtained from the activated sludge and the biomass in form of consortium will genrate electricity in return.The microbes oxidize the sludge for growth and metabolism of the consortia used.