Fig. 1: Cultured isolates are metabolically labeled by fluorescent oligosaccharides. | Nature Communications

Fig. 1: Cultured isolates are metabolically labeled by fluorescent oligosaccharides.

From: Identifying glycan consumers in human gut microbiota samples using metabolic labeling coupled with fluorescence-activated cell sorting

Fig. 1

a–c Synthesis of fluorescent β-cyclodextrin (a), nystose (b), and galactosyl-mannopentaose (c) probes. Mono-functionalized glycans were purified by reverse-phase chromatography, size-exclusion chromatography, or high-performance liquid chromatography (HPLC). The products were characterized by mass spectrometry. d Fluorescence measured from washed K. oxytoca (Proteobacteria) and L. acidophilus (Firmicutes) cultures after incubation in their respective minimum media with CD-F or NYST-F probe for 30 min, as measured on a spectrofluorometer. Data are the mean ± SD (n = 3). Statistical significance compared to the control condition by unpaired t-tests with Bonferroni-Dunn’s multiple comparison test. e Confocal microscopy image of fluorescently labeled K. oxytoca and 2-photon microscopy image of L. acidophilus after incubation with CD-F and NYST-F. Bacteria in the exponential phase were washed and incubated for 1 h with the probes (500 nM) and then fixed with 4% paraformaldehyde. f Fluorescence quantification of bacteria isolated from stool samples after incubation with free fluorescein (4.4 μM) or CD-F (4.4 μM) for 1 h with or without heat shock pretreatment of the gut microbiota for 10 min at 65 °C. Data are the mean ± SD (n = 3). Statistical significance compared to the labeled condition by one-way ANOVA with Bonferroni’s multiple comparison test. Source data and statistical details are provided as a Source data file.

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