IPROCAR Research Institute, Food Technology, University of Extremadura, Cáceres, 10003, Spain.
IPROCAR Research Institute, Food Hygiene and Safety, University of Extremadura, Cáceres, 10003, Spain.
Microb Biotechnol. 2022 Feb;15(2):668-682. doi: 10.1111/1751-7915.13723. Epub 2020 Dec 23.
This study aimed to provide insight into the molecular and genetic mechanisms implicated in the responses of Lactobacillus reuteri against the oxidative stress induced by malondialdehyde (MDA) by analysing protein oxidation and assessing the uspA and the dhaT genes. Four experimental groups were evaluated depending on the concentration of MDA added in Man, Rogosa and Sharpe (MRS) broth: Control (L. reuteri), 5 µM (L. reuteri + 5 µM MDA), 25 µM (L. reuteri + 25 µM MDA) and 100 µM (L. reuteri + 100 µM MDA). Three replicates were incubated at 37 °C for 24 h in microaerophilic conditions and sampled at 12, 16, 20 and 24 h. The upregulation of the uspA gene by L. reuteri indicates the recognition of MDA as a potential DNA-damaging agent. The dhaT gene, encoding a NADH-dependent-oxidoreductase, was also upregulated at the highest MDA concentrations. This gene was proposed to play a role in the antioxidant response of L. reuteri. The incubation of L. reuteri with MDA increased the production of ROS and caused thiol depletion and protein carbonylation. L. reuteri is proposed to detoxify pro-oxidative species while the underlying mechanism requires further elucidation.
本研究旨在通过分析蛋白质氧化并评估uspA 和 dhaT 基因，深入了解与乳杆菌（Lactobacillus reuteri）对丙二醛（MDA）诱导的氧化应激反应相关的分子和遗传机制。根据在 Man、Rogosa 和 Sharpe（MRS）肉汤中添加 MDA 的浓度，将四个实验组进行评估：对照（L. reuteri）、5µM（L. reuteri+5µM MDA）、25µM（L. reuteri+25µM MDA）和 100µM（L. reuteri+100µM MDA）。在微需氧条件下于 37°C 孵育 24 小时，在 12、16、20 和 24 小时时取样。uspA 基因的上调表明 L. reuteri 识别 MDA 为潜在的 DNA 损伤剂。编码 NADH 依赖性氧化还原酶的 dhaT 基因在最高 MDA 浓度下也被上调。该基因被提议在 L. reuteri 的抗氧化反应中发挥作用。L. reuteri 与 MDA 孵育会增加 ROS 的产生，并导致巯基耗竭和蛋白质羰基化。L. reuteri 被提议解毒促氧化物质，但其潜在机制需要进一步阐明。
