ABSTRACT
Gallic acid (GA) accumulation and tannase production by Aspergillus niger GH1 in submerged culture at different initial tannic acid concentrations (ITACs) (12.5, 25.0, 50.0, and 100 g/L) as sole carbon source were evaluated. The ability of the fungus to convert tannic acid to GA was determined byHigh Performance Liquid Chromatography (HPLC) and tannase production. Along with the GA determination, the kinetic parameters were calculated for the bioprocess optimization. The substrate concentration affected both the GA and tannase production by A. niger GH1. The maximum GA accumulation (more than 6 g/L), a highest tannase activity (6019 U/L), and the fastest tannic acid degradation were observed at lowest ITAC (12.5 g/L). In contrast, at 50 and 100 g/L ITAC, hydrolysis of tannic acid, and GA accumulation were strongly affected. In this study, the fungus was shown to exhibit intracellular tannase activity.
