Radiation of ionizing or non-ionizing nature has harmful effects on cellular components like DNA as radiation can compromise its proper integrity. To cope with damages caused by external stimuli including radiation, within living cells, several fast and efficient repair mechanisms have evolved. Previous studies addressing organismic radiation tolerance have shown that radiotolerance is a predominant property among extremophilic microorganisms including (hyper-) thermophilic archaea. The analysis of the ionizing radiation tolerance of the chemolithoautotrophic, obligate anaerobic, hyperthermophilic Crenarchaeon Ignicoccus hospitalis showed a D10-value of 4.7 kGy, fourfold exceeding the doses previously determined for other extremophilic archaea. The genome integrity of I. hospitalis after γ-ray exposure in relation to its survival was visualized by RAPD and qPCR. Furthermore, the discrimination between reproduction, and ongoing metabolic activity was possible for the first time indicating that a potential viable but non-culturable (VBNC) state may also account for I. hospitalis.

中文翻译：

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质疑生命的辐射极限：Ignicoccushospitalis 介于复制和 VBNC 之间

电离或非电离性质的辐射会对 DNA 等细胞成分产生有害影响，因为辐射会损害其适当的完整性。为了应对包括辐射在内的外部刺激造成的损害，在活细胞内，已经发展出几种快速有效的修复机制。先前针对有机体辐射耐受性的研究表明，辐射耐受性是包括（超）嗜热古细菌在内的极端嗜热微生物的主要特性。对化能自养型、专性厌氧型、超嗜热型 Crenarchaeon Ignicoccus hospitalis 的电离辐射耐受性的分析显示，D10 值为 4.7 kGy，是先前为其他极端嗜热古细菌确定的剂量的四倍。I的基因组完整性。通过 RAPD 和 qPCR 显示出 γ 射线暴露后住院患者的存活率。此外，生殖和持续代谢活动之间的区别首次成为可能，这表明潜在的可行但不可培养 (VBNC) 状态也可能导致 I.hospitalis。