Bacillus subtilis spore inactivation mechanisms under low energy electron beam (LEEB) and high energy electron beam (HEEB) treatment were investigated using seven mutants lacking specific DNA repair mechanisms. The results showed that most of the DNA repair-deficient mutants, including ΔrecA, ΔKu ΔligD, Δexo Δnfo, ΔuvrAB and ΔsbcDC, had reduced resistances towards electron beam (EB) treatments at all investigated energy levels (80 keV, 200 keV and 10 MeV) compared to their wild type. This result suggested DNA damage was induced during EB treatments. The mutant lacking recA showed the lowest resistance, followed by the mutant lacking Ku and ligD. These findings indicated that recA, Ku and ligD and their associated DNA repair mechanisms, namely, homologous recombination and non-homologous end joining, play important roles in spore survival under EB treatment. Furthermore, exoA, nfo, uvrAB, splB, polY1 and polY2, which are involved in nucleotide damage repair/removal, showed different levels of effects on spore resistance under EB treatment. Finally, the results suggested that HEEB and LEEB inactivate B. subtilis spores through similar mechanisms. This research will provide a better understanding of how EB technologies inactivate B. subtilis spores and will contribute to the application of these technologies as a non-thermal, gentle spore control approach.

中文翻译：

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DNA修复在枯草芽孢杆菌孢子对高能和低能电子束治疗的抗性中的作用。

利用七个缺乏特异性DNA修复机制的突变体，研究了低能电子束（LEEB）和高能电子束（HEEB）处理下的枯草芽孢杆菌孢子失活机制。结果表明，大多数DNA修复缺陷型突变体，包括ΔrecA，ΔKuΔligD，ΔexoΔnfo，ΔuvrAB和ΔsbcDC，在所有研究的能级（80 keV，200 keV和10 MeV）下，对电子束（EB）处理的抗性均降低。 ）与野生型相比。该结果表明在EB治疗期间诱导了DNA损伤。缺少recA的突变体显示出最低的抗性，其次是缺少Ku和ligD的突变体。这些发现表明recA，Ku和ligD及其相关的DNA修复机制，即同源重组和非同源末端连接，EB处理在孢子存活中起重要作用。此外，参与核苷酸损伤修复/去除的exoA，nfo，uvrAB，splB，polY1和polY2在EB处理下对孢子抗性表现出不同程度的影响。最后，结果表明HEEB和LEEB通过类似的机制灭活了枯草芽孢杆菌的孢子。这项研究将提供对EB技术如何灭活枯草芽孢杆菌孢子的更好理解，并将有助于这些技术作为非热温和孢子控制方法的应用。枯草芽孢通过类似的机制。这项研究将提供对EB技术如何灭活枯草芽孢杆菌孢子的更好理解，并将有助于这些技术作为非热温和孢子控制方法的应用。枯草芽孢通过类似的机制。这项研究将提供对EB技术如何灭活枯草芽孢杆菌孢子的更好理解，并将有助于这些技术作为非热温和孢子控制方法的应用。