Fungal strain Humicola lutea 120–5 was immobilized in poly[hydroxyethylmethacrylate (HEMA)-ethyleneglycoldimethacrylate (EDMA)] gel. Immobilized cells were cultivated in column and airlift bioreactors with different height to diameter (H/D) ratio for acid proteinases production during batch and repeated-batch processes. Influence of aeration rate in the bioreactors on enzyme production was studied. Optimal conditions for maximum proteinases production were obtained during repeated batch cultivation of immobilized cells (IC) in an airlift bioreactor with H/D=4 and aeration rate of 6 wm.