Aureobasidium pullulans (de Bary) Arnaud (Ach 1-1) was grown in a glucose fed-batch fermentor to 106 g dry wt l -1 in 48 h. The cells were dried in a fluidized bed dryer with a final viability of 62%. After 7 months at 4°C, the viability was 28% of the initial value (= 2.3 · 10 10 c.f.u. g -1 dry matter). A protection level of 89% was achieved with the biomass preparation at 1 · 10 8 c.f.u. ml -1 after 28 and 7 days for apples stored respectively at 5 and 25°C against Penicillium expansum. Our process is suitable to produce large quantities of the strain Ach 1-1 as biological control agent for apple preservation.