Single cell fluorescence imaging of glycan uptake by intestinal bacteria
Single cell fluorescence imaging of glycan uptake by intestinal bacteria
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DOI：
10.1038/s41396-019-0406-z
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发表时间：
2019-07-01
期刊：
影响因子：
11
通讯作者：
Abbott, D. Wade
中科院分区：
文献类型：
--
作者：
Hehemann, Jan-Hendrik;Reintjes, Greta;Abbott, D. Wade
哺乳动物肠道中的微生物降解食物聚糖以获得能量和生长。多糖利用所需的途径在功能上是多样的;此外，它们在细菌基因组之间不均匀地分散。因此，将代谢表型分配给基因型仍然是微生物组研究中的一个挑战。在这里，我们证明了肠道细菌中的聚糖摄取可以使用落射荧光显微镜用荧光聚糖缀合物（FGC）可视化。将酵母α-甘露聚糖和鼠李糖半乳糖醛酸-II（分别来自酵母和植物的细胞壁的两种结构不同的聚糖）荧光标记并进料至多形拟杆菌VPI-5482。野生型细胞迅速消耗FGC并变得荧光;而缺失聚糖降解和转运途径的菌株是非荧光的。因此，FGC的摄取是遗传功能的直接证据，并提供了在单细胞水平评估肠道细菌中特异性聚糖代谢的直接方法。
Microbes in the intestines of mammals degrade dietary glycans for energy and growth. The pathways required for polysaccharide utilization are functionally diverse; moreover, they are unequally dispersed between bacterial genomes. Hence, assigning metabolic phenotypes to genotypes remains a challenge in microbiome research. Here we demonstrate that glycan uptake in gut bacteria can be visualized with fluorescent glycan conjugates (FGCs) using epifluorescence microscopy. Yeast alpha-mannan and rhamnogalacturonan-II, two structurally distinct glycans from the cell walls of yeast and plants, respectively, were fluorescently labeled and fed to Bacteroides thetaiotaomicron VPI-5482. Wild-type cells rapidly consumed the FGCs and became fluorescent; whereas, strains that had deleted pathways for glycan degradation and transport were non-fluorescent. Uptake of FGCs, therefore, is direct evidence of genetic function and provides a direct method to assess specific glycan metabolism in intestinal bacteria at the single cell level.