US researchers have found how some micro-organisms can clean groundwater and produce electricity from renewable resources .This, say the findings of a group of scientists at Massachusetts Amherst University ,is thanks to Geobacter ,which they found in conductive and tiny structure called microbial nanowire and nanowires are only 3-5 nanometres thick (20,000 time finer than a human hair) ,but durable and more than a thousand times as long as they are wide. The discovery could also influence applications in nanotechnology The findings of the team ,led by microbiologist Derek R Lovley were published in Nature .Such long, thin conductive structures are unprecedented in biology ,says Lovley ,who also discovered Geobacter in 1987.These microbes are found useful in the bioremediation of groundwater contaminated with toxic and radioactive metals or petroleum and can convert human and animal wastes or renewable biomass into electricity Geobacter is a anaerobic bacteria (living without oxygen) that uses metals to gain energy the way humans and other organisms use oxygen. Early studies at Lovley’s lab revealed that Geobacter produces fine, hairlkie structures called the pili, on just one side of the cell. Lovley’s speculate that the pili, are miniature wires extending from the cell that would enable Geobacter to carry out its unique ability to transfer electrons outside the cell onto metals and electrodes .This was confirmed in a study where microbiologist Gemma Ruegera
teamed up with physicists Mark T Tuominen and Kevin D McCarthy to probe the pili with the high resolution atomic force microscope .They found the pili were highly conductive .When Geobacter was genetically modified to prevent it from producing the pili ,the bacteria could no longer transfer electrons.
The above article has appeared in the periodical bulletin of Institution of Enginers (India) who are always reputed for finding out such advanced Technological informations. They are the only recognised official institution of India for Engineers. Their certificates are considered to be equivalent to University Degrees and Post graduate degrees in Engineering (all specialisations ).