FIG. 1.

NMR spectra of the supernatant containing the end products derived from the fermentation of [1-¹³C]glucose by T. zilligii. The cell suspension (4.5 ml and 7-mg/ml protein concentration) was incubated with 15 mM [1-¹³C]glucose for 2 h at 75°C. (A) ¹³C NMR spectrum acquired on a Bruker DRX500 spectrometer using a 5-mm selective probe head (spectral width, 31 kHz; data size, 64,000; repetition delay, 61 s; pulse width, 7 μs). Proton decoupling was applied during the acquisition time (1 s). (B) ¹H NMR spectrum acquired on the same spectrometer with water presaturation (spectral width, 5 kHz; data size, 64,000; repetition delay, 17 s; pulse width, 7 μs). In the ¹³C NMR spectrum, resonances arising from nonmetabolized [1-¹³C]glucose are apparent in the region between 60 and 100 ppm. In the representation of the ¹H NMR spectrum, the strong intensity resonance due to the unlabeled methyl group of acetate has been truncated.