ACID PROTEINASES PRODUCTION BY HUMICOLA-LUTEA CELLS IMMOBILIZED IN POLYHYDROXYETHYLMETHACRYLATE GEL

The spores of Humicola lutea entrapped in polyhydroxyethylmethacrylate gel were precultivated in production medium for mycelial formation. T he immobilized mycelium was reused in batch mode for acid proteinases production. The influence of precultivation time, initial inoculum gel volume, and gel particle size on the enzyme activity and proteinases production half-life were studied. After 70 h precultivation of the en trapped spores (10 ml initial inoculum volume, 12-27 mm3 gel particle size) maximum proteinases activity of 100-140% (compared with free cel ls) was registered in 15 reaction cycles. Under the same conditions th e half-life time was 18 cycles, while for the free cells it was 5 cycl es. The main advantage of the polyhydroxyethylmethacrylate immobilized H. lutea was the long acid proteinases production half-life at a low concentration of out-growing cells in the medium.