Science publishes possible basis for radioprotective effect in D.radiodurans

["Strom, Daniel J" <strom@PNL.GOV>]

Here's a very interesting radiobiology discovery regarding the putative

radioprotective effect of Manganese (II) in D. radiodurans. 



Abstract: Deinococcus radiodurans is extremely resistant to ionizing

radiation. How this bacterium can grow under chronic gamma radiation [50

grays (Gy) per 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 with radiation-sensitive bacteria

and that resistance exhibits a concentration-dependent response to

manganous chloride [Mn(II)]. Among the most radiation-resistant

bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus, and

cyanobacteria accumulate Mn(II). In contrast, Shewanella oneidensis and

Pseudomonas putida have high iron but low intracellular manganese

concentrations and are very sensitive. We propose that Mn(II)

accumulation facilitates recovery from radiation injury.



Daly MJ, Gaidamakova EK, Matrosova VY, Vasilenko A, Zhai M,

Venkateswaran A, Hess M, Omelchenko MV, Kostandarithes HM, Makarova KS,

Wackett LP, Fredrickson JK, Ghosal D. Accumulation of Mn(II) in

Deinococcus radiodurans facilitates gamma-radiation resistance. Science

306(5698):1025-1028; 5 November 2004.



- Dan Strom



The opinions expressed above, if any, are mine alone and have not been

reviewed or approved by Battelle, the Pacific Northwest National

Laboratory, or the U.S. Department of Energy.



Daniel J. Strom, Ph.D., CHP

Environmental Technology Directorate, Pacific Northwest National

Laboratory

Mail Stop K3-56, PO BOX 999, Richland, Washington 99352-0999 USA

Overnight: Battelle for the U.S. DOE, 790 6th St., Richland WA 99354

ATTN: Dan Strom K3-56

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