Extracellular Amylase Production by Cassava-Fermenting Bacteria

Abstract

Fermentation of cassava tubers was accompanied by a gradual decrease in pH, increased amylase activity in the steep liquor, and increased microbial load and lactic acid concentration. Amylase-producing bacterial strains associated with cassava fermentation were isolated and identified as Bacillus subtilis, Bacillus licheniformis and Bacillus cereus. The pH optima for the partially purified enzymes of these organisms were 7.0, 5.5 and 7.5, whilst their temperature optima were 30, 37 and 80 oC. There was no significant difference in amylase activities when starch, dextrin, amylopectin, glucose and maltose were used as growth substrates.