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:10.3389/fmicb.2021.722347

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

Front Microbiol. 2021 Sep 1:12:722347. doi: 10.3389/fmicb.2021.722347. eCollection 2021.

Authors

Qingping Liang¹, Yuming Zhan², Mingxue Yuan¹, Linyuan Cao¹, Changliang Zhu¹, Haijin Mou¹, Zhemin Liu¹

Affiliations

¹ College of Food Science and Engineering, Ocean University of China, Qingdao, China.
² Shandong Provincial Key Laboratory of Quality Safety Monitoring and Risk Assessment for Animal Products, Jinan, China.

Abstract

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 k_cat/K_m values of the three recombinant mannanases ManAK^C292V, ManAK^L293V, and ManAK^L294H were enhanced by 303.0, 280.4, and 210.1%, respectively. Furthermore, ManAK^L293V 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: catalytic ability; consensus sequence design; rational design; thermostability; β-mannanase.