|
Isolation and identification of a thermophilic alpha-amylase-producing Bacillus strain from hot water sources in Auj city
|
Nazanin zahra Eftekhar   , Behzad Hemati * |
| Member of the academic faculty of Azad University, Karaj branch, rank 17 |
|
|
Abstract: |
Introduction: Alpha-amylases are the most important and widely used amylases in industry. Among alpha-amylases, thermophilic strains are of particular importance due to their stability and activity at high temperatures. Materials and Methods: In this study, sampling, isolation, and screening of alpha-amylase-producing bacterial strains, identification of the isolated bacterial strain, measurement of enzyme activity, measurement of alpha-amylase activity, effect of different carbon sources on alpha-amylase enzyme production, investigation of the effect of pH on alpha-amylase enzyme production, investigation of alpha-amylase enzyme thermal activity, investigation of alpha-amylase enzyme thermal stability were performed, respectively. Results: Based on the results of screening in special liquid and solid media, two strains with codes TSG59 and TSG70 were selected as superior strains. Molecular biochemical identification showed that TSG59 and TSG70 had the highest similarity to Bacillus licheniformis. The results of the optimization of the enzyme production medium showed that the production of bi-strain alpha-amylase TSG59 and TSG70 was highest in a medium containing 5 g/L starch, 2 g/L peptone, 1 g/L calcium chloride and pH 5, respectively, and in a medium containing 5 g/L starch, 2 g/L ammonium chloride, 1 g/L calcium chloride and pH 8. The maximum activity and stability of alpha-amylase TSG59 was observed at a temperature of 50 degrees Celsius, and for alpha-amylase TSG70, respectively, 60 and 70 degrees Celsius were achieved, the thermal stability of both TSG59 and TSG70 was improved by adding 20 mM calcium chloride.
|
|
| Keywords: Alpha-amylase, Production, Friend heat enzymes, Temperature activity, Temperature stability. |
|
|
|
|
Type of Study: Research |
Subject:
General
|
|
|
|
|
|
