A Novel Adaptation Mechanism Underpinning Algal Colonization of a Nuclear Fuel Storage Pond
Publication Date: 26 June, 2018
Algal growth in nuclear ponds
Spent nuclear fuel is stored underwater in large ponds prior to processing and disposal. Such environments are intensely radioactive, but new work from The University of Manchester has shown that they can be colonised by microorganisms. Colonisation of such inhospitable radioactive ponds is surprising, and the survival mechanisms that microbes use is of fundamental interest. It is also important to study these unusual ecosystems, as microbes growing in the pond waters may accumulate radionuclides present in the waters (offering the potential to bioremediate the waters), while high cell loadings can hamper management of the ponds due to poor visibility. In this first-of-a-kind study, an outdoor pond at the UK Sellafield facility was analysed by cutting-edge DNA sequencing, and shown to be colonised by a seasonal microbial bloom dominated by the alga Haematococcus, which was able to accumulate high levels of 137Cs and 90Sr. This organism is not normally associated with deep water bodies, but metabolomic analyses, and microscopy showed that it is able to adapt to radioactive environments via the production of the pigment astaxanthin, which can protect the cells from free radicals formed during irradiation. The team has now expanded its search for life to other ponds and facilities within the Sellafield complex, and the data from these studies are important to help support microbial growth control strategies.
- Microorganisms can survive in the most inhospitable environments on Earth, including nuclear facilities.
- Other environments where microbial life has been documented include hot springs, deep sea trenches, glaciers, salt lakes, mines and mine wastes.
- Microbes have lived on Earth for approximately 3.5 billion years, and have evolved many ways to survive in extreme environments