Deinococcus radiodurans is extremely resistant to ionizing radiation. How this bacterium can grow under chronic ?-radiation (50 Gy/hour) or recover from acute doses greater than 10 kGy is unknown. We show that D. radiodurans accumulates very high intracellular manganese and low iron levels compared to radiation sensitive bacteria, and resistance exhibits a concentration-dependent response to Mn(II). Among the most radiation-resistant bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus and cyanobacteria spp. accumulate Mn(II). In contrast, Shewanella oneidensis and Pseudomonas putida have high Fe but low intracellular Mn concentrations and are very sensitive. We propose that Mn(II) accumulation facilitates recovery from radiation injury.
Revised: October 27, 2005 |
Published: November 5, 2004
Citation
Daly M.J., E. Gaidamakova, V. Matrosova, A. Vasilenko, M. Zhai, A. Venkateswaran, and M. Hess, et al. 2004.Accumulation of Mn(II) in Deinococcus radiodurans Facilitates Gamma-Radiation Resistance.Science 306, no. 5698:1025-1028.PNNL-SA-42783.