Cowpea waste: A novel substrate for solid state production of amylase by Aspergillus oryzae

Cowpea waste moistened with minerals was used as the solid substrate for the production of glucoamylase by Aspergillus oryzae BS41. The waste supported mould growth and enzyme synthesis. Maximum glucoamylase synthesis (970U/ml) was obtained when fermentation was carried out at 72 h with an inoculum’s size, initial moisture and pH of 4%, 60% and 5.0 respectively at 28 ± 2°C. Supplementation with starch (2% w/v) as a carbon source enhanced glucoamylase production (1,500 U/ml) under optimized conditions while maltose adversely affected glucoamylase synthesis. Further supplementation with Soybean flour (3% w/v) gave a maximum amylase yield (2,333 U/ml) at 72 h. The study therefore presents cowpea waste as a cheap medium for the production of microbial amylase.