Highly thermostable and alkaline α-amylase from a halotolerant-alkaliphilic Bacillus sp. AB68

• Autor(a) principal: Aygan,Ashabil
• Data de Publicação: 2008
• Outros Autores: Arikan,Burhan, Korkmaz,Hatice, Dinçer,Sadik, Çolak,Ömer
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Microbiology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000300027
• topic: Bacillus sp.; α-amylase; alkaliphilic; thermostable; enzyme

An alkaliphilic and highly thermostable α-amylase producing Bacillus sp. was isolated from Van soda lake. Enzyme synthesis occurred at temperatures between 25ºC and 40ºC. Analysis of the enzyme by SDS-PAGE revealed a single band which was estimated to be 66 kDa. The enzyme was active in a broad temperature range, between 20ºC and 90ºC, with an optimum at 50ºC; and maximum activity was at pH 10.5. The enzyme was almost completely stable up to 80ºC with a remaining activity over 90% after 30 min pre-incubation. Thermostability was not increased in the presence of Ca2+. An average of 75% and 60ºC of remaining activity was observed when the enzyme was incubated between pH 5 and 9 for 1 h and for 2 h, respectively. The activity of the enzyme was inhibited by SDS and EDTA by 38% and 34%, respectively.