The optimization of some extracellular enzymes biosynthesis by Aspergillus niger 377-4

The effect of initial solid and moisture contents, temperature and time of incubation on the production of polygalacturonase, phytase, acid phosphatase, xylanase and β-glucanase by Aspergillus niger 377-4 during solid state fermentation was studied. Parameters of enzyme synthesis were optimized using statistical experimental designs. It was shown that the capacity of strain to synthesize the aforementioned enzymes could be modified within a wide range by culture parameters selection. The optimal polygalacturonase production efficiency was achieved with the initial medium mass of 19.9 g and humidity of 59.9%, after 77.7 h of incubation at 28.9C. The best combination of culture parameters for phytase synthesis was: initial medium mass 19.9 g, moistures 50%, temperature 33C and incubation time 83.9 h. The highest activity of acid phosphatase was obtained after 81.3 h of incubation at 27C, with initial substrate mass of 17.8 g and moistness content of 60%. The initial solid and moisture contents to synthesize xylanase were 19.9 g and 50%, respectively, with incubation time of 73 h at 29.6C. The highest efficiency of β-glucanase biosynthesis was obtained when A. niger 3774 was cultivated for 80.4 h at 27C on a initial medium mass of 20 g and initial level of moistness 59.9%.