Citation:
Abstract:
Azelaic acid is a dicarboxylic acid that has recently been shown to play a role in plant-bacteria signalling and also occurs naturally in several cereals. Several bacteria have been reported to be able to utilize azelaic acid as a unique source of carbon and energy, including <span class="jp-italic"> <span class="named-content-species"> <a class="namesforlife" href="http://doi.org/10.1601/nm.2652" rel="namesforlife-name" target="xrefwindow" title="Pseudomonas nitroreducens - Click to open Names for Life widget">Pseudomonas nitroreducens</a> </span> </span>. In this study, we utilize <span class="jp-italic"> <span class="named-content-species"> <a class="namesforlife" href="http://doi.org/10.1601/nm.2652" rel="namesforlife-name" target="xrefwindow" title="P. nitroreducens - Click to open Names for Life widget">P. nitroreducens</a> </span> </span> as a model organism to study bacterial degradation of and response to azelaic acid. We report genetic evidence of azelaic acid degradation and the identification of a transcriptional regulator that responds to azelaic acid in <span class="jp-italic"> <span class="named-content-species"> <a class="namesforlife" href="http://doi.org/10.1601/nm.2652" rel="namesforlife-name" target="xrefwindow" title="P. nitroreducens - Click to open Names for Life widget">P. nitroreducens</a> </span> </span> DSM 9128. Three mutants possessing transposons in genes of an acyl-CoA ligase, an acyl-CoA dehydrogenase and an isocitrate lyase display a deficient ability in growing in azelaic acid. Studies on transcriptional regulation of these genes resulted in the identification of an IclR family repressor that we designated as AzeR, which specifically responds to azelaic acid. A bioinformatics survey reveals that AzeR is confined to a few proteobacterial genera that are likely to be able to degrade and utilize azelaic acid as the sole source of carbon and energy.