Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia.
J Environ Radioact. 2011 Apr;102(4):407-11. doi: 10.1016/j.jenvrad.2011.02.011.
The effect of americium-241 ((241)Am), an alpha-emitting radionuclide of high specific activity, on luminous bacteria Photobacterium phosphoreum was studied. Traces of (241)Am in nutrient media (0.16-6.67 kBq/L) suppressed the growth of bacteria, but enhanced luminescence intensity and quantum yield at room temperature. Lower temperature (4 °C) increased the time of bacterial luminescence and revealed a stage of bioluminescence inhibition after 150 h of bioluminescence registration start. The role of conditions of exposure the bacterial cells to the (241)Am is discussed. The effect of (241)Am on luminous bacteria was attributed to peroxide compounds generated in water solutions as secondary products of radioactive decay. Increase of peroxide concentration in (241)Am solutions was demonstrated; and the similarity of (241)Am and hydrogen peroxide effects on bacterial luminescence was revealed. The study provides a scientific basis for elaboration of bioluminescence-based assay to monitor radiotoxicity of alpha-emitting radionuclides in aquatic solutions.
研究了高比活度的α放射性核素镅-241((241)Am)对发光细菌发光菌的影响。营养培养基中的痕量(241)Am(0.16-6.67 kBq/L)抑制了细菌的生长，但在室温下增强了发光强度和量子产率。较低的温度(4°C)增加了细菌发光的时间，并在生物发光开始 150 小时后揭示了生物发光抑制的阶段。讨论了细菌细胞暴露于(241)Am 的条件的作用。(241)Am 对发光细菌的影响归因于水溶液中作为放射性衰变的次级产物生成的过氧化物化合物。证明了(241)Am 溶液中过氧化物浓度的增加；并揭示了(241)Am 和过氧化氢对细菌发光的影响的相似性。该研究为基于生物发光的测定法的制定提供了科学依据，用于监测水相中的α发射放射性核素的放射性毒性。
