R. paludigenum was incubated as described above for two days with 10 l g/l patulin to induce patulin degradation activity. The cells were harvested, washed and the frozen cell paste was lyophilized. One gram of freeze-dried cells were ground, suspended in 10 ml ammonium acetate solution (NH 4 C 2 H 3 O 2 , 20 mM, pH 7.0) and the supernatant (namely protein solution) was collected by centrifugation at 4 ?C at 13,000g for 10 min. The assay for patulin degradation in the following tests contained 100 l l protein solution, 5 l g patulin and 400 l l NH 4 C 2 H 3 O 2 solution (20 mM).