Production and properties of alpha-amylase from thermophilic Bacillus sp.
alpha-amylase (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1) production by thermophilic Bacillus sp strain SMIA-2 cultivated in liquid media containing soluble starch reached a maximum at 48h, with levels of 57U/mL. Studies on the a-amylase characterization revealed that the optimum temperature for activity was 70ºC. The enzyme was stable for 2h at 50ºC, while at 60ºC, 70ºC and 90ºC, 4%, 13% and 38% of the original activities were lost, respectively. The optimum pH of the enzyme was 7.5. After incubation of crude enzyme solution for 24h at pH 7.5, a decrease of about 5% of its original activity was observed. The enzyme was strongly inhibited by Co2+, Cu2+ and Ba2+, but less affected by Ca2+, Mg2+, Ni2+, Sr2+ and Mn2+. The enzyme in 1M and 5M NaCl solutions the enzyme retained 70% and 47% of the original activity after 24h of incubation at 4ºC, respectively.
Main Authors: | , , |
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Format: | Digital revista |
Language: | English |
Published: |
Sociedade Brasileira de Microbiologia
2002
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Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000100012 |
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