- MIT Engineers have developed a method to screen bacteria based on their ability to generate electricity
- The method can be potentially used to generate power or cleanup environment
Bacteria’s ability to adapt and resilience is well known in scientific communities, and there are several bacteria that can survive in extreme environments from freezing conditions to boiling temperatures, withstand highly acidic or alkaline medium, survive radiation, and are even found deep in gold mines.
To withstand such extreme environments, these bacteria usually come up with a novel adaptation such as the ones that live in our gut that can produce electricity.
While a fuel-cell made of bacteria, also known has Microbial Fuel Cell (MFC), is a concept which scientists and engineers have been experimenting with for decades, the process has been largely inefficient and thus economically unviable.
Now a group of engineers from MIT, have developed a process that can identify and segregate bacteria that can produce electicity from the ones that can’t. The microfluidic technique uses polarizability to assess a bacteria’s ability to produce electricity in a more efficient manner compared to existing methods.
How to Bacteria generate electricity?
While the exact process varies, the bacteria generate electron within their cells and then transfer those electrons outside of their cell walls through surface proteins, this process is knows as extracellular electron transfer (EET).
How did MIT Engineers’ improving the electricity production using bacteria?
The existing techniques to harness electrochemical activity from bacteria involve growing large batches of cells. Then it either measures the activity of the EET proteins which is a very time consuming and cumbersome process or, breaks down the cell to extract the proteins that carry the electrons.
The MIT Engineers built microfluidic chips etched with small channels which look like an hourglass (pictured below) that has a small aperture. When an electric current is applied at the aperture, it either attracts or repels any object depending upon their properties. This process is known as dielectrophoresis and is usually used to sort bacteria by their size, species etc.
The MIT engineers working on the project, Cullen Buie and Qianru Wang, used the same process and modified it to sort by the electrical charge of the bacteria instead.
Different types of bacteria were trapped at different ranges of voltages and were measured for their sizes, the MIT team then calculated the “polarizability” of the cells which was a function of the voltage at which the bacteria was trapped and size of the cell. Polarizability is used to measure the ability to form dipoles. In layman terms, the higher the polarizability, the less voltage is required to trap them.
The MIT team then discovered from their calculations, that bacteria with more electrochemical activity had higher polarizability, i.e. the higher the polarizability the more electricity the bacteria can produce.
Using this method the MIT team claims the researchers can sort bacteria according to their electricity producing capabilities and build better Microbial Fuell Cells and even use it in power plants since the process is efficient and non-destructive.
What will MIT team’s process of sorting bacteria by their electricity producing capability impact?
Scientists have been exploring various uses of such electricity-producing bacteria, with NASA researching if they can be used to power future space missions. NASA researchers are exploring if bacteria which generate electric currents can be used to power essential functions on space missions in near future.
Microbial Fuel cells are also going to become cheaper to produce and more efficient. MFCs are touted as a potential key power source for IoT devices that require low power but replacing their batteries are impractical.
MFCs also can be used for wastewater treatment, a process that provide double benefits of producing electricity as well and cleaning wastewater.
Source: MIT News