Simple device to monitor aerobic biotransformations by in situ H-1-NMR

A simple device for taking in situ proton NMR measurements in (H2O)-H-1 is described. This allows aeration of reactions in a 10 mm diameter NMR tube w ithout modifying the magnet or the probe head. With this device, aerobic bi otransformations can be monitored in the NMR-tube placed in the spectromete r. It allows in situ analyses of the transformations, separating the aerati on period temporally from the measurement time, not unlike traditional Warb urg respiratory experiments. Two reactions determining kinetic and stoichie ometric parameters: (i) a biotransformation by a growing Pseudomonas putida culture and (ii) L-phenylalanine oxidation catalysed by L-amino acid oxida se [E.C. 1.4.3.2]; both incubations were contained in the magnet.