Multiple-Stress Tolerance of Ionizing Radiation-Resistant Bacterial Isolates Obtained from Various Habitats: Correlation Between Stresses
Multiple-Stress Tolerance of Ionizing Radiation-Resistant Bacterial Isolates Obtained from Various Habitats: Correlation Between Stresses
复制标题
从不同栖息地获得的抗电离辐射细菌分离株的多重应激耐受性：应激之间的相关性
作者：
Manish Shukla;R. Chaturvedi;D. Tamhane;P. Vyas;G. Archana;S. Apte;J. Bandekar;A. Desai
本文报道了从不同生境中筛选出五株耐电离辐射（IR）细菌的结果。IR抗性菌株对γ辐射表现出不同程度的抗性，可分为高、中抗两类。对紫外线辐射的抗性与对γ辐射的抗性具有很好的相关性，而所有高度和中度辐射抗性的菌株都具有相当的抗干燥性。但耐盐性与抗辐射性之间没有相关性，表明耐盐性和抗辐射性的进化是不同的。通过扩增的rDNA限制性内切酶分析图谱对分离株进行表征，证实了这些分离株与其胁迫表型的聚类。16S rRNA基因分析表明，具有相似抗性生理的菌株聚在一起，属于近缘属。过氧化氢抗性和丝裂霉素的生存模式的菌株表明，氧化胁迫耐受性的作用，脱水生存和重组修复，在更高的辐射抗性，分别。
Isolation of five ionizing radiation (IR)-resistant bacteria by screening of isolates from various habitats classified as common and stressed is reported. IR-resistant isolates exhibited varying degrees of resistance to γ-radiation and were classified as highly and moderately radiation resistant. Resistance to ultraviolet (UV) radiation correlated well with γ-radiation resistance, whereas a comparable desiccation resistance for all the highly and moderately radiation-resistant isolates was observed. However, salt tolerance failed to correlate with IR resistance, indicating a divergent evolution of the salt tolerance and radiation resistance. Characterization of isolates by the amplified rDNA restriction analysis profiling attested to the clustering of these isolates with their stress phenotype. 16S rRNA gene-based analysis of the isolates showed that the bacteria with similar-resistance physiologies clustered together and belonged to related genera. Hydrogen peroxide resistance and mitomycin survival patterns of the isolates indicated the roles of oxidative-stress tolerance in desiccation survival and recombination repair in higher radiation resistance, respectively.