Genome-wide investigation and functional characterization of the β-ketoadipate pathway in the nitrogen-fixing and root-associated bacterium Pseudomonas stutzeriA1501

BMC Microbiology

Research Article

Wei Liu¹  Lizhao Geng¹  Yongliang Yan¹  Ming Chen¹  Shuzhen Ping¹  Liang Li¹  Wenna Lin¹  Wei Zhang²  Wei Lu²  Danhua Li³  Min Lin³ 

[1] Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Crop Biotechnology, Ministry of Agriculture, 100081, Beijing, China;Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Crop Biotechnology, Ministry of Agriculture, 100081, Beijing, China;National Centre for Plant Gene Research, 100101, Beijing, China;College of Biological Sciences, China Agricultural University, 100094, Beijing, China;Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Crop Biotechnology, Ministry of Agriculture, 100081, Beijing, China;

关键词: Catechol;    Catabolite Repression;    Carbon Catabolite Repression;    Protocatechuate;    Complementary Plasmid;   

DOI  :  10.1186/1471-2180-10-36

 received in 2009-09-28, accepted in 2010-02-08,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundSoil microorganisms are mainly responsible for the complete mineralization of aromatic compounds that usually originate from plant products or environmental pollutants. In many cases, structurally diverse aromatic compounds can be converted to a small number of structurally simpler intermediates, which are metabolized to tricarboxylic acid intermediates via the β-ketoadipate pathway. This strategy provides great metabolic flexibility and contributes to increased adaptation of bacteria to their environment. However, little is known about the evolution and regulation of the β-ketoadipate pathway in root-associated diazotrophs.ResultsIn this report, we performed a genome-wide analysis of the benzoate and 4-hydroxybenzoate catabolic pathways of Pseudomonas stutzeri A1501, with a focus on the functional characterization of the β-ketoadipate pathway. The P. stutzeri A1501 genome contains sets of catabolic genes involved in the peripheral pathways for catabolism of benzoate (ben) and 4-hydroxybenzoate (pob), and in the catechol (cat) and protocatechuate (pca) branches of the β-ketoadipate pathway. A particular feature of the catabolic gene organization in A1501 is the absence of the catR and pcaK genes encoding a LysR family regulator and 4-hydroxybenzoate permease, respectively. Furthermore, the BenR protein functions as a transcriptional activator of the ben operon, while transcription from the catBC promoter can be activated in response to benzoate. Benzoate degradation is subject to carbon catabolite repression induced by glucose and acetate in A1501. The HPLC analysis of intracellular metabolites indicated that low concentrations of 4-hydroxybenzoate significantly enhance the ability of A1501 to degrade benzoate.ConclusionsThe expression of genes encoding proteins involved in the β-ketoadipate pathway is tightly modulated by both pathway-specific and catabolite repression controls in A1501. This strain provides an ideal model system for further study of the evolution and regulation of aromatic catabolic pathways.

【 授权许可】

Unknown   
© Li et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.