Screening on the Amylase Producing Activity of some Bacterial Strains Isolated from Hot Spring

Twelve bacterial strains were isolated from soil samples of hot springs. Among 12 bacterial isolates, 3 isolated bacterial strains showed the amylolytic activity. Cultural and morphological characteristics of the selected bacterial were studied. The quantitative determination of reducing sugar formation was carried out by using dinitrosalicylic acid (DNS) method in which starch was used as an inducer substrate for amylase enzyme. According to reducing sugar formation, T1, T2 and T3 showed the reducing sugar formation with the values of 2.986 mg/ml, 4.77 mg/ml and 2.805 mg/ml, respectively. The optimal incubation period for reducing sugar formation was found at 48 hours for T1 and at 36 hr for T2 and T3. The optimum incubation temperature for T2 was at 50 C whereas at 60 C was observed for T1 and T3. The optimum condition of pH 6.5 and PH 7 was observed in T1and T2, T3. The growth curve of effective bacteria T3 strain was studied. The growth rate of these bacteria reached maximum value (7.0x108cfu/ml) at 60C and 36hrs of incubation period.