Studies in which Biam has participated show that the photosynthetic lake bacterium Gloeomargarita lithophora traps radioactive elements such as strontium and radium. These results open the way to a process for decontaminating environmental water or radioactive effluents.
There are photosynthetic bacteria capable of mineralizing the calcium present in water to form solid calcium carbonate. This process is at the origin of the formation of limestone rocks over geological times. Certain lacustrine bacteria biomineralize calcium, but also other alkaline earths such as barium, strontium and radium, which are radioactive.
Researchers at Sorbonne University have demonstrated that one of these bacteria, Gloeomargarita lithophora, is selective and primarily mineralizes barium (Ba), even in the presence of excess calcium. In collaboration with a Biam researcher, they tested the ability of this bacterium to trap alkaline earths such as strontium and radium, which can be a problem in water in the event of environmental contamination. Radium-226 is a natural radioactive element, strontium-90 is a radioactive element produced by nuclear fission. In both cases, the radioactive element was fully biomineralized in the intracellular granules in the presence of an excess of calcium.
Preliminary experiments on saturated strontium-90 solutions have shown the good behavior of the cells and the conservation of their strontium trapping capacity. These experiments open the way to the use of this cyanobacterium to decontaminate strontium and radium from environmental waters or radioactive effluents. The cyanobacterium developing by photosynthesis, the process can be implemented in open basins or in photobioreactors.