摘要:In this study invertase activity expression in Aspergillus niger Aa-20 was evaluated under different concentrations of two substrates using solid-state fermentation (SSF) on polyurethane foam. Glucose was used as repressor and sucrose was the inducer. Invertase production increased when glucose was present in the medium (up to 100 g/L); however, higher concentration than this reduced the enzyme production. Induction-repression ratio obtained using any glucose concentration was at least 2.5 times higher than that under basal conditions (without inducer).