Radiation Resistance among Bacteria

Thornley, Margaret J.

doi:10.1111/j.1365-2672.1963.tb04784.x

Cited by 83 publications

(38 citation statements)

References 36 publications

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“…A number of microorganisms possess the ability to transform uranium from contaminated soils and sediments to less soluble and less toxic chemical state [54,264,282,[284][285][286][287][288]. This potential is considered very attractive for establishing certain remediation strategies because of its low cost, as well as of short-term studies supporting its feasibility [54,282,[289][290][291].…”

Section: Biomineralization Formation Of Insoluble Metal Sulphides Anmentioning

confidence: 98%

Characterization and remediation of soils contaminated with uranium

Gavrilescu¹,

Pavel²,

Creţescu³

2009

Journal of Hazardous Materials

503

195

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Section: Biomineralization Formation Of Insoluble Metal Sulphides Anmentioning

confidence: 98%

Characterization and remediation of soils contaminated with uranium

Gavrilescu¹,

Pavel²,

Creţescu³

2009

Journal of Hazardous Materials

503

195

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“…Similarly, vegetative cells of Bacillus spp. cannot grow at 6 kilorads/h and Bacillus spores show a 5-order-of-magnitude decrease in viability following acute exposure to 200 to 1,000 kilorads (207).…”

Section: Isolationmentioning

confidence: 99%

Genome of the Extremely Radiation-Resistant Bacterium Deinococcus radiodurans Viewed from the Perspective of Comparative Genomics

Makarova

Aravind

Wolf

et al. 2001

Microbiol Mol Biol Rev

646

612

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The bacterium Deinococcus radiodurans shows remarkable resistance to a range of damage caused by ionizing radiation, desiccation, UV radiation, oxidizing agents, and electrophilic mutagens. D. radiodurans is best known for its extreme resistance to ionizing radiation; not only can it grow continuously in the presence of chronic radiation (6 kilorads/h), but also it can survive acute exposures to gamma radiation exceeding 1,500 kilorads without dying or undergoing induced mutation. These characteristics were the impetus for sequencing the genome of D. radiodurans and the ongoing development of its use for bioremediation of radioactive wastes. Although it is known that these multiple resistance phenotypes stem from efficient DNA repair processes, the mechanisms underlying these extraordinary repair capabilities remain poorly understood. In this work we present an extensive comparative sequence analysis of the Deinococcus genome. Deinococcus is the first representative with a completely sequenced genome from a distinct bacterial lineage of extremophiles, the Thermus-Deinococcus group. Phylogenetic tree analysis, combined with the identification of several synapomorphies between Thermus and Deinococcus, supports the hypothesis that it is an ancient group with no clear affinities to any of the other known bacterial lineages. Distinctive features of the Deinococcus genome as well as features shared with other free-living bacteria were revealed by comparison of its proteome to the collection of clusters of orthologous groups of proteins. Analysis of paralogs in Deinococcus has revealed several unique protein families. In addition, specific expansions of several other families including phosphatases, proteases, acyltransferases, and Nudix family pyrophosphohydrolases were detected. Genes that potentially affect DNA repair and recombination and stress responses were investigated in detail. Some proteins appear to have been horizontally transferred from eukaryotes and are not present in other bacteria. For example, three proteins homologous to plant desiccation resistance proteins were identified, and these are particularly interesting because of the correlation between desiccation and radiation resistance. Compared to other bacteria, the D. radiodurans genome is enriched in repetitive sequences, namely, IS-like transposons and small intergenic repeats. In combination, these observations suggest that several different biological mechanisms contribute to the multiple DNA repair-dependent phenotypes of this organism

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“…However, the role of the metabolic repertoire and physiological state of D. radiodurans at the time of irradiation has been characterized far less. Little is known about this relationship other than that (i) exponentially growing D. radiodurans cells are more sensitive to radiation than stationary-phase cells are (22,31), (ii) increasing the concentration of Mn 2ϩ in cells decreases genomic redundancy along with radiation resistance (6), and (iii) freezing or desiccating D. radiodurans substantially increases its radiation resistance (7,18,26).…”

mentioning

confidence: 99%

Physiologic Determinants of Radiation Resistance in Deinococcus radiodurans

Venkateswaran

McFarlan

Ghosal

et al. 2000

Appl Environ Microbiol

127

116

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Immense volumes of radioactive wastes, which were generated during nuclear weapons production, were disposed of directly in the ground during the Cold War, a period when national security priorities often surmounted concerns over the environment. The bacterium Deinococcus radiodurans is the most radiationresistant organism known and is currently being engineered for remediation of the toxic metal and organic components of these environmental wastes. Understanding the biotic potential of D. radiodurans and its global physiological integrity in nutritionally restricted radioactive environments is important in development of this organism for in situ bioremediation. We have previously shown that D. radiodurans can grow on rich medium in the presence of continuous radiation (6,000 rads/h) without lethality. In this study we developed a chemically defined minimal medium that can be used to analyze growth of this organism in the presence and in the absence of continuous radiation; whereas cell growth was not affected in the absence of radiation, cells did not grow and were killed in the presence of continuous radiation. Under nutrient-limiting conditions, DNA repair was found to be limited by the metabolic capabilities of D. radiodurans and not by any nutritionally induced defect in genetic repair. The results of our growth studies and analysis of the complete D. radiodurans genomic sequence support the hypothesis that there are several defects in D. radiodurans global metabolic regulation that limit carbon, nitrogen, and DNA metabolism. We identified key nutritional constituents that restore growth of D. radiodurans in nutritionally limiting radioactive environments.

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Radiation Resistance among Bacteria

Cited by 83 publications

References 36 publications

Characterization and remediation of soils contaminated with uranium

Characterization and remediation of soils contaminated with uranium

Genome of the Extremely Radiation-Resistant Bacterium Deinococcus radiodurans Viewed from the Perspective of Comparative Genomics

Physiologic Determinants of Radiation Resistance in Deinococcus radiodurans

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