Molecules (Feb 2024)

A Recombinant Thermophilic and Glucose-Tolerant GH1 β-Glucosidase Derived from Hehua Hot Spring

  • Qian Zhu,
  • Yuying Huang,
  • Zhengfeng Yang,
  • Xingci Wu,
  • Qianru Zhu,
  • Hongzhao Zheng,
  • Dan Zhu,
  • Zhihua Lv,
  • Yirui Yin

DOI
https://doi.org/10.3390/molecules29051017
Journal volume & issue
Vol. 29, no. 5
p. 1017

Abstract

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As a crucial enzyme for cellulose degradation, β-glucosidase finds extensive applications in food, feed, and bioethanol production; however, its potential is often limited by inadequate thermal stability and glucose tolerance. In this study, a functional gene (lq-bg5) for a GH1 family β-glucosidase was obtained from the metagenomic DNA of a hot spring sediment sample and heterologously expressed in E. coli and the recombinant enzyme was purified and characterized. The optimal temperature and pH of LQ-BG5 were 55 °C and 4.6, respectively. The relative residual activity of LQ-BG5 exceeded 90% at 55 °C for 9 h and 60 °C for 6 h and remained above 100% after incubation at pH 5.0–10.0 for 12 h. More importantly, LQ-BG5 demonstrated exceptional glucose tolerance with more than 40% activity remaining even at high glucose concentrations of 3000 mM. Thus, LQ-BG5 represents a thermophilic β-glucosidase exhibiting excellent thermal stability and remarkable glucose tolerance, making it highly promising for lignocellulose development and utilization.

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