Exo-inulinase involved in utilization of the plant storage polymer inulin, consisting of fructooligosaccharides with a degree of polymerization (DP) value from 2 to 60. Splits off terminal fructose units successively from the non-reducing end of the inulin molecule. Hydrolysis of terminal, non-reducing (2->1)- and (2->6)-linked beta-D-fructofuranose residues in fructans. Optimum pH is 6.0. Optimum temperature is 60 degrees Celsius. Expression is up-regulated by inulin and maltose, and repressed by glucose. Ammonium sulfate, ammonium chloride and urea are inhibitory for inulinase synthesis, presumably because of the release of ammonium ions. Belongs to the glycosyl hydrolase 32 family.