Figure 3.

F. prausnitzii produces excess fructose and butyrate from inulin. F. prausnitzii was grown in bacterial broth containing inulin as sole sugar source and analyzed for (a) bacterial growth, (b) medium acidification, (c) inulin metabolism and fructose production, as well as the production of the short-chain fatty acids (SCFAs) butyrate (d), propionate (e) and acetate (f). Time-dependent growth of F. prausnitzii is associated with medium acidification, decrease in inulin (large polymers in C) and increase in fructose (asterisks in inset in C) and butyrate (D). Note that fructose levels increase particularly when F. prausnitzii is in the stationary growth phase (24–48 h), while butyrate levels increase most during the exponential growth phase (12–24 h). Propionate and acetate are endogenous components of the bacterial broth (at 8 and 30 mM, respectively) and their concentrations do not significantly change during F. prausnitzii growth on inulin. All experiments were performed with two biological replicates, each with an N = 3. *P < .05