Journal of Environmental Treatment Techniques  
2020, Volume 8, Issue 3, Pages: 952-960  
J. Environ. Treat. Tech.  
ISSN: 2309-1185  
Journal web link: http://www.jett.dormaj.com  
Screening, Characterization and Production of  
Thermostable Alpha-Amylase Produced by a Novel  
Thermophilic Bacillus megaterium Isolated from  
Pediatric Intensive Care Unit  
1
1
2*  
2
Seyyedeh Narjes Abootalebi , Amir Saeed , Ahmad Gholami , Milad Mohkam , Aboozar  
3
3
4
5
Kazemi , Navid Nezafat , Seyyed Mojtaba Mousavi , Seyyed Alireza Hashemi , Eslam  
Shorafa2*  
1
Department of Pediatrics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran  
2
Biotchnology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran  
3
Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran  
4
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan  
5
Department of Mechanical Engineering, Center for Nanofibers and Nanotechnology, National University of Singapore, Singapore  
Received: 09/03/2020  
Accepted: 13/06/2020  
Published: 20/09/2020  
Abstract  
This study aimed to isolate the thermophilic Bacillus strain capable of producing a high amount of thermo-stable α-amylase.The  
screening and isolation of amylase producing bacteria were done on selective media. The identification of bacteria was made using  
routine biochemical and molecular 16s rRNA techniques. The amylase activity assay was performed by using dinitrosalicylic acid (DNS)  
m
method, and finally, the optimum temperature, K (Michaelis constant) and maximum rate of reaction (Vmax) of the enzyme was  
calculated. Results: The newly thermo-stable amylolytic enzymes of Bacillus megaterium designated AGH01was isolated from pediatric  
intensive care unit through a selective enrichment procedure. This isolate was identified based on biochemical and morphological traits  
along with 16s rRNA partial sequence analysis. This isolate showed the highest amylolytic activity (19.2 U/mL after 24 h) as compared  
to other isolates. The optimum temperature for the enzyme activity was achieved at 90°C and pH 7.0. At this condition, K