Solid-state fermentation enhances inulinase and invertase production by Aspergillus brasiliensis

Extracellular inulinase and invertase production by Aspergillus brasiliensis was evaluated in solid-state fermentation (SSF) and submerged fermentation (SmF) with a high sucrose concentration. The parameters estimated from online CO2 analysis revealed a lower Lag phase in SSF compared to SmF; the specific CO2 production rate (mu CO2) decreased in both systems as the sucrose concentration increased. The highest maximum CO2 production rate (10.45 +/- 0.72 mg/h mL) and total CO2 production (138.53 +/- 6.48 mg/mL) were obtained in SSF with a sucrose concentration of 210 g/L. Inulinase and invertase production (1.13 +/- 0.02 and 5.84 +/- 0.12 U/mL, respectively) in SmF was independent of the initial sucrose concentration; meanwhile, both activities increased in SSF as the sucrose concentration increased, reaching maximum values of 5.88 +/- 0.78 and 41.69 +/- 3.60 U/mL, respectively, at the highest sucrose concentration (210 g/L). The zymographic analysis showed one band of inulinase and two bands of invertases involved in sucrose hydrolysis.