IMMOBILIZATION OF ACID PROTEINASE PRODUCER HUMICOLA-LUTEA 120-5 WITH PHOTO-CROSS-LINKABLE PREPOLYMER

Spores of fungal strain Humicola lutea 120-5 were immobilized with pho to-crosslinkable prepolymer. The entrapped spores were allowed to germ inate and develop in situ. The immobilized growing mycelium thus obtai ned was reused in batch mode for extracellular acid proteinase product ion. The influence of prepolymer concentration, initial inoculum gel v olume, spore content, and duration of the growth cycle on the enzyme a ctivity and mycelium growth were studied. The best yield of the acid p roteinase was reached with 15 ml initial gel volume, 20% prepolymer co ncentration, 10(6) spores per ml gel and 56 h duration of one cycle. T he optimization of these factors, which affect the stability and produ ctivity of the immobilized system, resulted in the increase of the enz yme activity (up to 180% compared with free cells), decrease of concen tration of outgrowing cells in the medium, and the realization of semi continuous cultivation. The productive life was nearly 10-12-times lon ger, and the cumulative enzyme activity was 18-times higher in compari son with those of free culture. Therefore, the immobilized growing Hum icola lutea 120-5 in the photo-crosslinked polymer could be used for a long-term production of an acid proteinase.