Features Saturday, September 13, 2014 - 05:30
The News Minute | September 10, 2014 | 4.00 pm IST Tiny single-cell organisms discovered living under the ground could help with the problem of nuclear waste disposal, says a study. The bacteria were found in a highly alkaline industrial site in the Peak district in Britain. The extremophile - organism that thrives in pysically or geochemically extreme conditions that are detrimental to most life on the Earth - bacteria can thrive under the alkaline conditions expected in cement-based radioactive waste, the researchers said. Although bacteria with waste-eating properties have been discovered in relatively pristine soils before, this is the first time that microbes that can survive in the very harsh conditions expected in radioactive waste disposal sites have been found. "It is highly likely that similar bacteria will behave in the same way and adapt to living off ISA (isosaccharinic acid) in and around buried cement-based nuclear waste sites quite quickly," said one of the researchers, professor Jonathan Lloyd from the University of Manchester. Isosaccharinic acid (ISA) in nuclear waste can react with a wide range of radionuclides - unstable and toxic elements that are formed during the production of nuclear power and make up the radioactive component of nuclear waste. If the ISA binds to radionuclides, such as uranium, then the radionuclides will become far more soluble and more likely to flow out of the underground vaults to surface environments, where they could enter drinking water or the food chain. "The newly discovered microorganisms may prevent this from becoming a problem," the researchers noted. The organisms are not only superbly adapted to live in such hostile environments but they can use the ISA as a source of food and energy under conditions that mimic those expected in and around intermediate level radioactive waste disposal sites. For example, when there is no oxygen (a likely scenario in underground disposal vaults) to help these bacteria "breathe" and break down the ISA, these micro-organisms are able to switch their metabolism on using other chemicals in the water, such as nitrate or iron. The findings appeared in the Multidisciplinary Journal of Microbial Ecology (ISME). IANS

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