Back to Search
Start Over
Purification and properties of a new thermostable cyclodextrin glucanotransferase from Bacillus pseudalcaliphilus 8SB.
- Source :
-
Applied biochemistry and biotechnology [Appl Biochem Biotechnol] 2011 Nov; Vol. 165 (5-6), pp. 1285-95. Date of Electronic Publication: 2011 Sep 06. - Publication Year :
- 2011
-
Abstract
- A new cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) from an alkaliphilic halotolerant Bacillus pseudalcaliphilus 8SB was studied in respect to its γ-cyclizing activity. An efficient conversion of a raw corn starch into only two types of cyclodextrins (β- and γ-CD) was achieved by the purified enzyme. Crude enzyme obtained by ultrafiltration was purified up to fivefold by starch adsorption with a recovery of 62% activity. The enzyme was a monomer with a molecular mass 71 kDa estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and native PAGE. The CGTase exhibited two pH optima, at pH 6.0 and 8.0, and was at most active at 60 °C and pH 8.0. The enzyme retained more than 80% of its initial activity in a wide pH range, from 5.0 to 11.0. The CGTase was strongly inhibited by 15 mM Cu(2+), Fe(2+), Ag(+), and Zn(2+), while some metal ions, such as Ca(2+), Na(+), K(+), and Mo(7+), exerted a stimulating effect in concentration of 5 mM. The important feature of the studied CGTase was its high thermal stability: the enzyme retained almost 100% of its initial activity after 2 h of heating at 40-60 °C; its half-life was 2 h at 70 °C in the presence of 5 mM Ca(2+). The achieved 50.7% conversion of raw corn starch into 81.6% β- and 18.4% γ-CDs after 24 h enzyme reaction at 60 °C and pH 8.0 makes B. pseudalcaliphilus 8SB CGTase industrially important enzyme for cyclodextrin production.
- Subjects :
- Bacillus chemistry
Bacillus genetics
Bacillus isolation & purification
Bacterial Proteins genetics
Bacterial Proteins metabolism
Cyclodextrins metabolism
Enzyme Stability
Glucosyltransferases genetics
Glucosyltransferases metabolism
Hydrogen-Ion Concentration
Kinetics
Molecular Sequence Data
Soil Microbiology
Substrate Specificity
Temperature
Bacillus enzymology
Bacterial Proteins chemistry
Bacterial Proteins isolation & purification
Glucosyltransferases chemistry
Glucosyltransferases isolation & purification
Subjects
Details
- Language :
- English
- ISSN :
- 1559-0291
- Volume :
- 165
- Issue :
- 5-6
- Database :
- MEDLINE
- Journal :
- Applied biochemistry and biotechnology
- Publication Type :
- Academic Journal
- Accession number :
- 21894524
- Full Text :
- https://doi.org/10.1007/s12010-011-9346-4