Specific Determination of Amylase Activity in Crude Extracts from Fermented Cassava (Manihot esculenta) Tubers

Fermentation of cassava tubers with amylase-producing bacterial and fungal strains was accompanied with increase in amylase activity. Tubers with Saccharomyces cerevisae showed the maximum unit and specific activity (7.75 unit/ml and 0.55 unit/min/mg). The optimum activity of crude extract of fermented sample was at temperature 40°C for Bacillus cereus, 60°C for Saccharomyces cerevisae and 30°C for Aspergillus niger, whilst the optimum pH was at 7.5 for Bacillus cereus, 6.5 for Saccharomyces cerevisae and 5.5 for Aspergillus niger. The maximum amylase activity was at substrate concentration of 5% for Bacillus cereus, Saccharomyces cerevisae and Aspergillus niger. The potential of these microorganisms in solid state fermentation were great.