Fig. 5: Alanine racemase activities in bacteria, conventional and germ-free mice.
From: Biodistribution and racemization of gut-absorbed l/d-alanine in germ-free mice
a Illustration of alanine racemase activity converting l-Ala-2,3,3,3-d4 to d-Ala-3,3,3-d3. b–e Concentrations of d-Ala-3,3,3-d3 in samples from germ-free mice after two-week feeding of l-Ala-2,3,3,3-d4 or regular water as control. g–j Concentrations of d-Ala-3,3,3-d3 in samples from conventional mice 1-h after gavage feeding of solution containing the same stable isotope labeled l-Ala or saline as control. Pairwise comparisons using Mann–Whitney tests (two-tailed for germ-free and one-tailed for conventional mice) were performed between the control and dosed groups individually for each sample type. f Racemization of l-Ala-2,3,3,3-d4 in bacterial culture. One-tailed Mann–Whitney tests were used to compare between time zero and the two other time points individually. Each data point represents one sample from one individual animal (n = 4 for germ-free and n = 3 for conventional mice) or one tube of bacterial biomass (n = 3). Asterisks with brackets indicate statistical significance (U = 0, complete separation). Floating bars indicate minimum and maximum, and the middle lines indicate median. SI: small intestine.
