Schwanbeck Julian, Oehmig Ines, Groß Uwe, Bohne Wolfgang
Institute for Medical Microbiology and Virology, University Medical Center, Göttingen, Germany.
Biotechnology Institute, University of Minnesota, Saint Paul, MN, United States.
Front Microbiol. 2023 Mar 30;14:1172707. doi: 10.3389/fmicb.2023.1172707. eCollection 2023.
As many gastro-intestinal pathogens, the majority of strains express flagella together with a complete chemotaxis system. The resulting swimming motility is likely contributing to the colonization success of this important pathogen. In contrast to the well investigated general energy metabolism of , little is known about the metabolic requirements for maintaining the ion motive force across the membrane, which in turn powers the flagellar motor. We studied here systematically the effect of various amino acids and carbohydrates on the swimming velocity of using video microscopy in conjunction with a software based quantification of the swimming speed. Removal of individual amino acids from the medium identified proline and cysteine as the most important amino acids that power swimming motility. Glycine, which is as proline one of the few amino acids that are reduced in Stickland reactions, was not critical for swimming motility. This suggests that the ion motive force that powers the flagellar motor, is critically depending on proline reduction. A maximal and stable swimming motility was achieved with only four compounds, including the amino acids proline, cysteine and isoleucine together with a single, but interchangeable carbohydrate source such as glucose, succinate, mannose, ribose, pyruvate, trehalose, or ethanolamine. We expect that the identified "minimal motility medium" will be useful in future investigations on the flagellar motility and chemotactic behavior in , particularly for the unambiguous identification of chemoattractants.
与许多胃肠道病原体一样，大多数菌株表达鞭毛并伴有完整的趋化系统。由此产生的游动运动可能有助于这种重要病原体的定殖成功。与对[病原体名称未提及]广泛研究的一般能量代谢不同，对于维持跨膜离子动力势的代谢需求了解甚少，而跨膜离子动力势又为鞭毛马达提供动力。我们在此使用视频显微镜结合基于软件的游动速度量化方法，系统地研究了各种氨基酸和碳水化合物对[病原体名称未提及]游动速度的影响。从培养基中去除单个氨基酸后发现，脯氨酸和半胱氨酸是驱动游动运动的最重要氨基酸。甘氨酸与脯氨酸一样，是斯特克兰德反应中少数被还原的氨基酸之一，但对游动运动并不关键。这表明为鞭毛马达提供动力的离子动力势严重依赖于脯氨酸的还原。仅用四种化合物就能实现最大且稳定的游动运动，这四种化合物包括氨基酸脯氨酸、半胱氨酸和异亮氨酸以及单一但可互换的碳水化合物源，如葡萄糖、琥珀酸盐、甘露糖、核糖、丙酮酸、海藻糖或乙醇胺。我们预计，所确定的“最小运动培养基”将有助于未来对[病原体名称未提及]鞭毛运动和趋化行为的研究，特别是用于明确鉴定化学引诱剂。
