2.2.3. Enzymatic activity
Enzyme activity was determined using starch as substrate (1% w/v in 100 mM citrate-phosphate buffer at pH 6.0). Starch hydrolysis (50◦C) was monitored by determination of reducing sugar using dinitrosalicylic acid method at 540 nm [27]. A standard curve was prepared with maltose. One beta-amylase activity unit (U) was defined as the amount of enzyme capable of producing 1 Mol of maltose per minute under assay conditions.