ere conducted to illustrate the effects of different factors on the color parameters.

Electronic supplementary material
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Dataset 1

**Electronic supplementary material**

**Supplementary information** accompanies this paper at 10.1038/s41598-017-17238-9.

**Publisher\'s note:** Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The authors are grateful for the financial support provided by the fundamental research funds for the central universities (2572016EBJ1).

Xiaodong Zhu conceived and designed the experiments; Ningwen Dong performed the experiments; Zhao Li analyzed the data; Xiaodong Zhu and Yu Liu wrote the paper.

Competing Interests {#FPar1}
===================

The authors declare that they have no competing interests.


Background
==========

The *Deinococcaceae*are a small family within the domain *Bacteria*that are distinguished by their ability to tolerate DNA double strand breaks \[[@B1],[@B2]\]. There are eleven validly described species and seven of these tolerate what for most microorganisms is a sterilizing dose of ionizing radiation, exhibiting detectable survival after exposure to 10 kGy (1,000,000 Rad) γ radiation \[[@B3]\]. The ionizing radiation resistance of the four remaining species, *Deinococcus indicus*\[[@B4]\], *Deinococcus frigens*, *Deinococcus saxicola*, and *Deinococcus marmoris*\[[@B5]\] has not been reported. Ionizing radiation generates an array of DNA damage in the target cell, including many types of base damage, single, and double strand breaks \[[@B6]\]. Of these types of damage, DNA double strand breaks (DSBs) are considered the greatest threat to cell viability, and an excessive number of DSBs are expected to be lethal. *E. coli*, for example, cannot survive introduction of greater than one or two DSBs into its genome \[[@B7]\]. In contrast, *D. radiodurans*survives doses of ionizing radiation that generate greater than 100 DSBs per genome without mutati