Bacteria in mud samples have been transformed into microbial fuel cells generating enough electricity to power a toy car — just part of a larger phenomenon that one chemical engineer had originally dismissed as “complete nonsense.”
Science magazine remembers how Lars Peter Nielsen’s 2009 experiment at Denmark’s Aarhus University changed the way the world viewed bacteria:
At the start of the experiment, the muck was saturated with hydrogen sulfide — the source of the sediment’s stink and color. But 30 days later, one band of mud had become paler, suggesting some hydrogen sulphide had gone missing. Eventually, the microsensors indicated that all of the compound had disappeared….
The first explanation, he says, was that the sensors were wrong. But the cause turned out to be far stranger: bacteria that join cells end to end to build electrical cables able to carry current up to 5 centimeters through mud. The adaptation, never seen before in a microbe, allows these so-called cable bacteria to overcome a major challenge facing many organisms that live in mud: a lack of oxygen. Its absence would normally keep bacteria from metabolizing compounds, such as hydrogen sulfide, as food. But the cables, by linking the microbes to sediments richer in oxygen, allow them to carry out the reaction long distance.
Slashdot reader sciencehabit calls it one of the discoveries “forcing researchers to rewrite textbooks; rethink the role that mud bacteria play in recycling key elements such as carbon, nitrogen, and phosphorous; and reconsider how they influence aquatic ecosystems and climate change. Scientists are also pursuing practical applications, exploring the potential of cable and nanowire bacteria to battle pollution and power electronic devices.”
of this story at Slashdot.
Source:: Slashdot