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language
eng
Author
Sano, Tomoki
Description
Herbicides 2,4-dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading Bradyrhizobium strains possess tfdAα and/or cadABC as degrading genes. It has been reported that root-nodulating bacteria belonging to Bradyrhizobium elkanii also have tfdAα and cadA like genes but lack the ability to degrade these herbicides and that the cadA genes in 2,4-D-degrading and non-degrading Bradyrhizobium are phylogenetically different. In this study, we identified cadRABCK in the genome of a type strain of soybean root-nodulating B. elkanii USDA94 and demonstrated that the strain could degrade the herbicides when cadABCK was forcibly expressed. cadABCK-cloned Escherichia coli also showed the degrading ability. Because co-spiked phenoxyacetic acid (PAA) could induce the degradation of 2,4-D in B. elkanii USDA94, the lack of degrading ability in this strain was supposed to be due to the low inducing potential of the herbicides for the degrading gene cluster. On the other hand, tfdAα from B. elkanii USDA94 showed little potential to degrade the herbicides, but it did for 4-chlorophenoxyacetic acid and PAA. The 2,4-D-degrading ability of the cad cluster and the inducing ability of PAA were confirmed by preparing cadA deletion mutant. This is the first study to demonstrate that the cad cluster in the typical root-nodulating bacterium indeed have the potential to degrade the herbicides, suggesting that degrading genes for anthropogenic compounds could be found in ordinary non-degrading bacteria.
Subject
2,4-Dichlorophenoxyacetic acid
2,4,5-Trichlorophenoxyacetic acid
Herbicide-degrading gene
Non-degrading bacterium
Soybean root-nodulating bacterium
Bradyrhizobium elkanii USDA94
Journal Title
Microbiological Research
Volume
188
Start Page
62
End Page
71
ISSN
09445013
Published Date
2016-07
DOI
DOI Date
2016-09-09
NCID
AA11017780
Publisher
Elsevier
NII Type
Journal Article
Format
PDF
Rights
© 2016 Elsevier GmbH. All rights reserved.
Text Version
著者版
OAI-PMH Set
Faculty of Life and Environmental Science
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