Journal: Applied and Environmental Microbiology

Article Title: Lactate cross-feeding between Bifidobacterium species and Megasphaera indica contributes to butyrate formation in the human colonic environment

doi: 10.1128/aem.01019-23

Figure Lengend Snippet: Substrate utilization during monoculture and coculture fermentation. (A and B; E and F) The concentration of xylose and xylo-oligosaccharides in the medium with BWX30 as the carbohydrate source. (C and D; G and H) Profile of the oligomers in the medium with BWX30 as the carbohydrate source. X1, xylose; X2, xylobiose; X3, xylotriose; X4, xylotetraose; X5, xylopentaose; X6, xylohexaose. The range bars in line charts denote the standard deviation of three biological replicates.

Article Snippet: Culture supernatants (4 µL) were loaded onto a CarboPac PA100 analytical column (4 × 250 mm) and eluted with the mobile phase made up of solution A (0.1 M NaOH) and solution B (1 M NaOAc with 0.1 M NaOH) at a flow rate of 1 mL/min following the gradient setting at the following settings: 0–35 min, 85% A and 15% B; 35–45 min, 50% A and 50% B; and 45–50 min, 100% A and 0% B; and a final washing step was carried out by running 100% A for 10 min. Quantification of the xylose oligomers with a degree of polymerization smaller than six was based on the standard curves that were prepared by mixed standard solutions composed of xylobiose (X2), xylotriose (X3), xylotetraose (X4), xylopentaose (X5), and xylohexaose (X6) that were purchased from Megazyme (Wicklow, Ireland). . Quantification of bacterial metabolites The concentration of the short-chain fatty acids (acetate, propionate, and butyrate) was determined by gas chromatography.

Techniques: Concentration Assay, Standard Deviation