Fig 3.

Volatile compound concentrations following nitrogen addition during the stationary phase of FSCF. ▲, ammonium pulse in the third stage of FSCF; ♢, valine pulse in the third stage of FSCF; dashed line, concentration in the tank without nitrogen addition; the solid line reports the evolution of metabolite concentration due only to washout of the tank (production rate = 0). Isobutanol, isoamyl alcohol, propanol, ethyl decanoate, ethyl hexanoate, ethyl acetate, hexyl acetate, and isobutyl acetate concentrations are expressed in mg/liter. One representative experiment of three biological replicates is shown.