This study was carried out to evaluate the process of phytase production by Aspergillus niger in solid-state fermentation (SSF) using triticale waste. A waste that currently has no use was reported for this biotechnological process, and is of high impact due to the null use. The process was carried out using an additive free medium, supplemented with only one nitrogen source. Under these conditions, phytase activity of 7.45 U/g dry substrate (DS) was obtained. The process was optimized using different additives such as dextrose, lactose, Tween 80 and potassium chloride. For fermentation maximization, two experimental designs were used: 1) Plackett-Burman design (PBD) and 2) the Box-Behnken design (BBD). PBD was used to evaluate the effect of related variables on the production of phytase, as well as their level of significance in the process, while BBD was used for optimal conditions determination. The process was conducted with Petri dishes and a maximum enzyme activity of 25.8 IU/g DS was obtained. Subsequently, SSF was carried out in a tray to increase the amount of fermented substrate and phytase activity of 23.63 IU/g DS was obtained. The results of this study suggest a minimal decrease (8.4%) in enzyme production with scaling.
Key words: Triticale, solid-state fermentation, phytase, Aspergillus niger, optimization, statistical experimental design.