Recombinant expression and characterization of an organic-solvent-tolerant α-amylase from Exiguobacterium sp. DAU5.
Appl Biochem Biotechnol
; 169(6): 1870-83, 2013 Mar.
Article
em En
| MEDLINE
| ID: mdl-23344941
ABSTRACT
The enzyme from halophilic microorganisms often has unique properties such as organic-solvent-tolerance. In this study, a novel organic-solvent-tolerant α-amylase gene was cloned from the mild halophile Exiguobacterium sp. DAU5. The open reading frame (ORF) of the enzyme consisted of 1,545 bp and encoded 514 amino acids, the primary sequence revealed that it belongs to the glycoside hydrolase (GH) family 13. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed an AmyH monomer of 57 kDa. The enzyme exhibited maximal activity at 40 °C in pH 8.5 glycine-NaOH buffer, and the activity was strongly inhibited by Zn(2+), Cu(2+), and Fe(2+). The α-amylase AmyH exhibited high hydrolysis activity toward soluble starch, and the major hydrolysis products were maltose, maltotriose, and maltopentaose; the AmyH could not efficiently hydrolyze oligosaccharides smaller than maltoheptaose, nor could it act on the ß-1,4 or α-1,6 glucosidic bonds in xylan or pullulan, respectively. In addition, the α-amylase exhibited better tolerance to organic solvents, as it was stable in the presence of dimethylsulfoxide (DMSO), methanol, ethanol, and acetone. Base on all of these results, the enzyme could be useful for practical application in the bakery industry and in biotechnological processes that occur in the presence of organic solvents.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Compostos Orgânicos
/
Solventes
/
Proteínas Recombinantes
/
Alfa-Amilases
/
Bacillales
Idioma:
En
Revista:
Appl Biochem Biotechnol
Ano de publicação:
2013
Tipo de documento:
Article