| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4364960 | International Biodeterioration & Biodegradation | 2013 | 7 Pages |
•A chlorpyrifos degrading bacterium Klebsiella sp. CPK was isolated by enrichment culture technique.•This strain could transform chlorpyrifos to 3,5,6-trichloro-2-pyridinol, but it could not degrade 3,5,6-trichloro-2-pyridinol.•The relA is responsible for (p)ppGpp accumulation in this strain with chlorpyrifos stress.•The relA expression enhances the tolerance of this strain to chlorpyrifos.
A chlorpyrifos-degrading bacterium, Klebsiella sp. CPK, which can biodegrade chlorpyrifos and transform it into 3,5,6-trichloro-2-pyridinol, was isolated by the enrichment culture technique. A classic stringent response triggered by chlorpyrifos stress was identified through the detection of (p)ppGpp accumulation in this strain. Sequence analysis of the (p)ppGpp synthetase RelA in Klebsiella sp. CPK showed that it only had (p)ppGpp synthetase activity. Compared to its parent, the △relA strain was more sensitive to several stress conditions, such as high salt, low pH values and a high concentration of chlorpyrifos. In addition, growth curves and semi-quantitative RT-PCR indicated that chlorpyrifos stress affected the growth and relA expression. Together, these results indicated that chlorpyrifos could mount a stringent response in the Klebsiella sp. CPK strain, and relA expression modulated the response of the Klebsiella sp. CPK strain to chlorpyrifos stress.
