Frontiers in Microbiology (Sep 2021)

Improvement of the Catalytic Ability of a Thermostable and Acidophilic β-Mannanase Using a Consensus Sequence Design Strategy

  • Qingping Liang,
  • Yuming Zhan,
  • Mingxue Yuan,
  • Linyuan Cao,
  • Changliang Zhu,
  • Haijin Mou,
  • Zhemin Liu

DOI
https://doi.org/10.3389/fmicb.2021.722347
Journal volume & issue
Vol. 12

Abstract

Read online

In order to improve the catalytic efficiency of a thermostable and acidophilic β-mannanase (ManAK; derived from marine Aspergillus kawachii IFO 4308), three mutants were designed by amino acid sequence consensus analysis with a second β-mannanase (ManCbs), which also belongs to the glycoside hydrolase family 5 (GH5) and has excellent catalytic efficiency. Three mutants were constructed and their biochemical characteristics were measured after heterologous expression in Pichia pastoris. The results revealed that the kcat/Km values of the three recombinant mannanases ManAKC292V, ManAKL293V, and ManAKL294H were enhanced by 303.0, 280.4, and 210.1%, respectively. Furthermore, ManAKL293V showed greater thermostability than ManAK, retaining 36.5% of the initial enzyme activity after incubation at 80°C for 5min. This study therefore provides a rational design strategy based on consensus sequence analysis to develop industrially valuable β-mannanase for future applications in marine aquafeed.

Keywords