THE INFLUENCE OF SEED ON THE SYNTHESIS AND SECRETION OF KERATINASE PENICILLIUM CITRINUM

Keratinases are the promising drugs for therapy and use in different fields were keratins should be hydrolyzed. Their obtaining from animal tissues is limited by the insufficient their content; however there is a possibility of enzymes production by various microorganisms. The aim of this investigation was to study the effect of vegetative inoculum on synthesis of keratinase, secreted by Penicillium citrinum for enhance of deuteromycete productivity.The study used the following methods: surface culturing in the Čapek medium, submerged cultivation on a modified Čapek medium, keratinolytic activity in the filtrates of the culture fluid ninhydrin method definition, microscopy. The study of the dynamics of exoproteases accumulation in the culture fluid was conducted. Spore suspension or 3-days mycelium were used as sowing material. It is shown that the use of vegetative sowing material instead of spores caused enzymatic activity increasing from 9.2 to 14.8 μm/mgхh and reduction of fermentation time from 10 to 6 days. The variation of concentration of vegetative sowing material allowed regulating the level of synthesis and dynamics of accumulation of keratinolytic enzymes. The introduction into a nutrient medium of thiamine at a concentration of 10 mg/l led to an additional increase of enzyme activity in the culture fluid by 44%. The most ideal conditions of P. citrinum cultivation were selected: inductor – 2% hair keratin, sowing material – vegetative mycelium in the amount of 10%, thiamine - 10 mg/l.