Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M²S), Katholieke Universiteit Leuven, Leuven, Belgium.
Appl Environ Microbiol. 2011 May;77(10):3422-7. doi: 10.1128/AEM.02763-10. Epub 2011 Mar 25.
During fermentation of sugars, a number of bacterial species are able to switch from mixed acid production to acetoin and 2,3-butanediol production in order to avoid lethal acidification of their environment, although the regulation of this switch is only poorly understood. In this study, we report the identification of the budAB structural operon, involved in acetoin production in Serratia plymuthica RVH1, and its activation by a LysR-type regulator encoded by budR, immediately upstream of this operon. In addition, the regulation of budR transcription was elucidated and found to be subject to negative control by BudR itself and to positive control by external stimuli such as N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) quorum sensing signaling molecules and acetate. Interestingly, however, we observed that induction of budR transcription by OHHL or acetate did not require BudR, indicating the involvement of additional regulatory factors in relaying these environmental signals to the budR promoter.
在糖发酵过程中，许多细菌物种能够从混合酸生产切换到乙酰酮和 2,3-丁二醇生产，以避免其环境发生致命酸化，尽管这种转换的调节机制还知之甚少。在这项研究中，我们报告了鉴定参与粘质沙雷氏菌 RVH1 中乙酰酮生产的 budAB 结构操纵子的情况，以及由 budR 编码的 LysR 型调节剂对该操纵子的激活作用。此外，阐明了 budR 转录的调控，并发现其受到 BudR 自身的负调控，以及外部刺激（如 N-(3-氧代己酰基)-L-高丝氨酸内酯 (OHHL) 群体感应信号分子和乙酸）的正调控。然而，有趣的是，我们观察到 OHHL 或乙酸诱导 budR 转录并不需要 BudR，这表明在将这些环境信号传递到 budR 启动子时涉及其他调节因子。
