Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. It is a member of a large group of unicellular microorganisms which have cell walls but lack of nucleus.
Who discovered the electrical Properties of Bacteria?
Bacteria can produce electricity and that it can be harnessed by energy generation systems has been known for quite some time.
University of Minnesota and University of California at Berkeley have experimented with a technique that studies on samples of bacteria and gauges. The bacteria has a specific property that shows their ability to produce electricity. far back as 2003 Daniel Bond and Derek Lovely had showcased how the Geobacter sulfurreducens bacteria can be used to generate electricity by creating microbial fuel cells.
What is Geobacter sulfurreducens bacteria?
These bacteria found on the bottom of lakes and on the sea bed. But now scinetist also find it find in our guts which is stomach or belly. Due to the size of bacteria which are too little to analysing their exact electrical properties, the scientist found it difficult to identify.
How the Scientist of MIT found its electrical properties.
The researchers mounted and channeled the bacteria on microfluidic chips. Microfluidic chip is a set of micro-channels etched or molded into a material such as glass or silicon.The micro-channels forming the microfluidic chip are connected together in order to achieve the desired features that is to mix, pump, sort, or control the biochemical environment. Then they subjected the bacteria to an electric field. But in the middle of the chip there was an enhanced electric field to create a slope with the surroundings.
The scientists did this by pinching the middle of the chip, reducing its width by 100 times.
The gradient of the electric field creates a phenomenon known as dielectrophoresis, or a force that makes the cell move in a direction opposite to that induced by the applied electric field. Based on the polarisability of the bacteria (electrical properties of their surfaces) they either get repelled or stopped in their tracks. The ones which had higher polarisability were also found to be electrochemically active. This, in turn, could become a source to identify the bacteria that have useful electrical properties. The research group studied many strains of bacteria including bio engineered ones and detailed their electrical properties.
How it works?
Bacteria produce electricity by a process known as extracellular electron transfer (EET). The microbes do this by generating electrons within their cells, then transferring them across their cell membranes through tiny channels formed by surface proteins. Some bacteria even form long surface proteins and extensions to build a network of electricity producing bacteria, especially those living on river banks.
They are studying these new strains of bacteria using the microfluidic dielectrophoresis technique. If the same trend of correlation stands for those newer strains, then this technique can have a broader application, in clean energy generation, bioremediation, and bio-fuel production,” said Qianru Wang one of the authors of the paper and a post doctoral researcher at MIT.