Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
Microbiologyopen. 2018 Aug;7(4):e00586. doi: 10.1002/mbo3.586. Epub 2018 Feb 9.
Chemoautotrophic bacteria belonging to the genus Sulfurimonas in the class Campylobacteria are widespread in many marine environments characterized by redox interfaces, yet little is known about their physiological adaptations to different environmental conditions. Here, we used liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in a targeted metabolomics approach to study the adaptations of Sulfurimonas denitrificans to varying salt concentrations that are found in its natural habitat of tidal mudflats. Proline was identified as one of the most abundant internal metabolites and its concentration showed a strong positive correlation with ionic strength, suggesting that it acts as an important osmolyte in S. denitrificans. 2,3-dihydroxypropane-1-sulfonate was also positively correlated with ionic strength, indicating it might play a previously unrecognized role in osmoregulation. Furthermore, the detection of metabolites from the reductive tricarboxylic acid cycle at high internal concentrations reinforces the importance of this pathway for carbon fixation in Campylobacteria and as a hub for biosynthesis. As the first report of metabolomic data for an campylobacterial chemolithoautotroph, this study provides data that will be useful to understand the adaptations of Campylobacteria to their natural habitat at redox interfaces.
属于 Campylobacteria 类的硫磺单胞菌属的化能自养细菌广泛存在于许多以氧化还原界面为特征的海洋环境中，但对于它们对不同环境条件的生理适应知之甚少。在这里，我们使用液相色谱串联质谱 (LC-MS/MS) 进行靶向代谢组学方法研究了硫磺单胞菌对其天然潮汐泥滩栖息地中发现的不同盐浓度的适应。脯氨酸被确定为最丰富的内部代谢物之一，其浓度与离子强度呈强正相关，表明它在硫磺单胞菌中作为一种重要的渗透调节剂。2,3-二羟基丙烷-1-磺酸酯也与离子强度呈正相关，表明它可能在渗透调节中发挥以前未被认识到的作用。此外，高内部浓度的还原性三羧酸循环代谢物的检测增强了该途径在 Campylobacteria 中固定碳和作为生物合成中心的重要性。作为化能自养营营菌代谢组学数据的首次报告，本研究提供的数据将有助于了解 Campylobacteria 对氧化还原界面自然栖息地的适应。
