Skip to main content
Log in

Directed evolution of α-amylase from Bacillus licheniformis to enhance its acid-stable performance

  • Original Article
  • Published:
Biologia Aims and scope Submit manuscript

Abstract

α-Amylases (1,4-α-D-glucanohydrolases) are widely used in starch liquefaction, but their acid stability needs to be continuously explored to reduce the costs of raw material and operation. In this study, to better meet the industrial requirements, the acid stability of Bacillus licheniformis α-amylase (BLA) was further improved by directed evolution using error prone polymerase chain reaction (PCR). The mutant BLA (G81R) was selected with the improved acid stability based on a high-throughput activity assay. After incubating at pH 4.5 for 40 min, G81R still retained 10% of its initial activity, but the wild-type (WT) was already inactive. The kcat/Km value of G81R at pH 4.5 was 1.4-fold higher than that of WT. Combined with the three-dimensional structural modeling analysis, the improved stability of G81R under low pH condition might be due to the interactions of electrostatic, hydrophilicity, and helix propensity. Therefore, these findings would be beneficial for developing BLA with properties suitable for applications in industrial starch processing.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

Abbreviations

BAA:

Bacillus amyloliquefaciens α-amylase

BLA:

Bacillus licheniformis α-amylase

CAZy:

Carbohydrate-Active enZymes α-amylase

GSA:

Geobacillus stearothermophilus α-amylase

GTA:

Geobacillus thermoleovorans α-amylase

IPTG:

isopropyl β-D-1-thiogalactopyranoside

LB:

Luria-Bertani

PCR:

polymerase chain reaction

PFA:

Pyrococcus furiosus α-amylase

SDS-PAGE:

sodiumdodecyl sulfate-polyacrylamide gel electrophoresis α-amylase

THA:

Thermococcus hydrothermalis α-amylase

WT:

wild-type

References

Download references

Acknowledgments

This work was supported by the National Key R&D Program of China (2017YFD0201405-04); the China Postdoctoral Science Foundation (2018 M641660); the Tianjin Natural Science Fund of China (17JCYBJC23700); and the Public Service Platform Program of Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control (17PTGCCX00190).

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Fuping Lu or Yihan Liu.

Ethics declarations

Conflict of interest

The authors declare no conflict of interest.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Huang, L., Shan, M., Ma, J. et al. Directed evolution of α-amylase from Bacillus licheniformis to enhance its acid-stable performance. Biologia 74, 1363–1372 (2019). https://doi.org/10.2478/s11756-019-00262-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.2478/s11756-019-00262-7

Keywords

Navigation