Thermostable mutant variants of Bacillus sp. 406 α-amylase generated by site-directed mutagenesis

Abstract: Several mutations are known to increase the thermostability of α-amylase of B. licheniformis and other α-amylases. Site-directed mutagenesis was used to introduce similar mutations into the sequence of the α-amylase gene from mesophilic Bacillus sp. 406. The influence of the mutations on thermostability of the enzyme was studied. It was shown that the Gly211Val and Asn192Phe substitutions increased the half-inactivation temperature (Tm) of the enzyme from 51.94±0.45 to 55.51±0.59 and 58.84±0.68°C respectively, in comparison to the wild-type enzyme. The deletion of Arg178-Gly179 (dRG) resulted in an increase of Tm of the α-amylase to 71.7±1.73°C. The stabilising effect of mutations was additive. When combined they increase the Tm of the wild-type amylase by more than 26°C. Thermostability rates of the triple mutant are close to the values which are typical for industrial heat-stable α-amylases, and its ability to degrade starch at 75°C was considerably increased. The present research confirmed that the Gly211Val, Asn192Phe and dRG mutations could play a significant role in thermostabilization of both mesophilic and thermophilic α-amylases.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Thermostable mutant variants of Bacillus sp. 406 α-amylase generated by site-directed mutagenesis ; volume:8 ; number:4 ; year:2013 ; pages:346-356 ; extent:11 ; Open life sciences ; 8, Heft 4 (2013), 346-356 (gesamt 11)

Contributors, Places and Time

• Creator: Kachan, Alexandr ; Evtushenkov, Anatoliy

Further information

• DOI: 10.2478/s11535-013-0142-0
• URN: urn:nbn:de:101:1-2409211543031.511086840694
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:21 AM CEST