Temperature-upshift-mediated revival from the sodium-pyruvate-recoverable viable but nonculturable state induced by low temperature in Ralstonia solanacearum: linear regression analysis
Temperature-upshift-mediated revival from the sodium-pyruvate-recoverable viable but nonculturable state induced by low temperature in Ralstonia solanacearum: linear regression analysis
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DOI：
10.1007/s10327-009-0166-0
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发表时间：
2009-06-01
影响因子：
1.2
通讯作者：
Nakaho, Kazuhiro
中科院分区：
文献类型：
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作者：
Imazaki, Iori;Nakaho, Kazuhiro
在应激损伤的细菌细胞中诱导了活但不可培养（VBNC）状态。VBNC细胞在标准培养基上失去了生长能力，但在补充了H(2)O(2)降解化合物（如丙酮酸钠（SP））的培养基上，一些细胞可以恢复。在这里，能够在这种介质上恢复的VBNC细胞称为sp -可恢复的VBNC细胞；不能恢复的VBNC细胞称为sp -不可恢复的VBNC细胞。在前人研究的基础上，我们假设，在低温环境中诱导sp可恢复的VBNC状态的枯枯菌细胞，在中等温度条件下可以恢复在标准固体培养基上的生长能力。为了验证这一点，我们将茄青的细胞悬浮液在5A℃下孵育，当只有sp可恢复的VBNC细胞存在时，将细胞悬浮液暴露在25A℃下，温度升高导致在标准固体培养基上能够生长的活性细胞数量开始迅速增加，随后逐渐增加。线性回归分析表明，这种增加不是由于残余活性细胞的低水平再生。此外，所有复活的细胞都在易感番茄植株上引起了枯萎症状。当5℃微环境中仅存在sp -不可恢复的VBNC细胞时，将细胞悬液暴露于25℃，此时未检测到可培养细胞。因此，这些数据强烈表明，sp可恢复的VBNC细胞在温度升高后在标准固体培养基上恢复了生长能力，并且恢复的细胞具有毒性。
The viable but nonculturable (VBNC) state is induced in stress-injured bacterial cells. VBNC cells lose their ability to grow on standard media, but some of the cells can recover on media supplemented with H(2)O(2)-degrading compounds such as sodium pyruvate (SP). Here, VBNC cells that can recover on such media are called SP-recoverable VBNC cells; VBNC cells that do not recover are called SP-unrecoverable VBNC cells. On the basis of previous findings, we hypothesized that cells of Ralstonia solanacearum in which low temperature had induced the SP-recoverable VBNC state would regain their ability to grow on standard solid media after exposure to moderate temperature. To test this, cell suspensions of R. solanacearum were incubated at 5A degrees C. When SP-recoverable VBNC cells were the only culturable cells present, the cell suspensions were exposed to 25A degrees C. The temperature upshift caused an initial rapid increase in the number of active cells able to grow on standard solid media, followed by a more gradual increase. Linear regression analyses suggested that this increase was not attributable to the regrowth of a low level of residual active cells. In addition, all the revived cells tested caused wilt symptoms in susceptible tomato plants. When SP-unrecoverable VBNC cells were the only viable cells present in the 5A degrees C microcosms, the cell suspensions were exposed to 25A degrees C. In this case, no culturable cells were detected. Therefore, these data strongly suggest that the SP-recoverable VBNC cells regained their ability to grow on standard solid media after the temperature upshift and that the revived cells were virulent.