Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and Other Robust Bacteria Contaminated Subsurface Environments of the Hanford Site.

摘要

In the last 3 years year, we have published twelve papers. The following is a summary of those publications and how they relate to our original NABIR goals. Until recently, there have been no clear physiologic predictors of a cells ability to recover from ionizing radiation (IR) and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus & Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella & Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny, where very high and very low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this bacterium to IR.