Purification, characterization, and statistical optimization of a thermostable α-amylase from desert actinobacterium Streptomyces fragilis DA7-7

Abstract

In this study, preliminary screening revealed that of 134 desert soil actinobacterial isolates, only 43 isolates produced amylase. Among these, an isolate DA7-7, which was identified as DA7-7, showed a prominent zone of clearance and significant amount of α-amylase production. The pre-optimization studies showed varying physicochemical and nutrients properties of the medium influenced the enzyme production significantly. Consequently, central composite design was employed with the selected variables (pH, temperature, dextrose, and peptone) for α-amylase production. The optimum fermentation conditions were 3.07% dextrose, 1.085% peptone, pH 6.0, and incubation temperature 27.27 °C. The predicted optimum α-amylase activity was 991.82 U/mL/min, which was similar to the experimental amylase activity of 973.5 U/mL/min. The crude α-amylase produced by DA7-7 was purified with ammonium sulfate precipitation, followed by gel filtration chromatography, and the estimated molecular mass was 51 kDa. The purified α-amylase was stable under the following conditions: pH (4-9), temperature (40-80 °C), NaCl (1-4 M), and detergents (1-10 mM). The and values of enzyme were found to be 0.624 mU/mg and 0.836 mg/mL, respectively.

Microbial Alpha-Amylase Production: Progress, Challenges and Perspectives

“…15 Actinomycetes, such as Streptomyces fragilis DA7-7 produce thermostable alpha-amylase. 29 Other microbial sources of alpha-amylase for commercial purposes include Aspergillus niger, Aspergillus awamori, and Aspergillus oryzae. 14 Due to the extracellular secretion of alpha-amylase that is easily isolatable from the microbial culture medium, fungi can be a good source for α-amylase production in the industry.…”

Characterization of Thermostable Amylase From Halophilic Lactobacillus Plantarum TS1

“…The amylase was exposed to various concentrations of sodium chloride i.e. 0 to 4 M. The reaction mixture along with various concentrations of NaCl (0 to 4 M) was incubated at 50 °C and the activity was monitored as mentioned above (Nithya et al 2017…”

Production and application of glucose isomerase from Streptomyces enissocaesilis and amylase from Streptomyces sp. for the synthesis of high fructose corn syrup

“…Yassien and Asfour [30] reported amylase from Streptomyces clavifer exhibiting maximum activity at the range of 40-50 °C. Industrially enzyme working at a moderate temperature of 35-40 °C is advantageous as this temperature range can be economically maintained [31].…”