Characterization of a Cu2+, SDS, alcohol and glucose tolerant GH1 β-glucosidase from Bacillus sp. CGMCC 1.16541

• Published in: Antonie van Leeuwenhoek Vol. 113; no. 10; pp. 1467 - 1477
• Main Authors: Yin, Yi-Rui, Sang, Peng, Yang, Feng-Li, Li, Tao, Yang, Run-Feng, Liu, Hong-Yan, Luo, Zong-Long, Li, Wen-Jun, Yang, Li-Quan
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.10.2020; Springer Nature B.V
• Subjects: Alcohol; Alcohols; Amino acid sequence; Amino acids; Bacillus; Bagasse; Biomedical and Life Sciences; Cellobiase; Cellobiose; Cellulase; Cellulose; Copper; Cupric ions; Drug tolerance; E coli; Glucose; Glucose tolerance; Glucosidase; Industrial applications; Life Sciences; Medical Microbiology; Microbiology; Molecular weight; Original Paper; p-Nitrophenyl-b-D-glucopyranoside; pH effects; Plant Sciences; Sodium dodecyl sulfate; Sodium lauryl sulfate; Soil Science & Conservation; Sugarcane; Xylopyranoside; β-Glucosidase; Glucose tolerance; β-Glucosidase; Cu; SDS; Alcohol; sp; Heterogeneous expression
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-020-01455-w

A β-glucosidase gene ( bsbgl1a ) from Bacillus sp. CGMCC 1.16541 was expressed in Escherichia coli BL21 and subsequently characterized. The amino acid sequence shared 83.64% identity with β-glucosidase (WP_066390903.1) from Fictibacillus phosphorivorans . The recombinant β-glucosidase (BsBgl1A) had a molecular weight of 52.2 kDa and could hydrolyze cellobiose, cellotriose, cellotetrose, p-nitrophenyl-β- d -glucopyranoside ( p NPG), and p-nitrophenyl-β- d -xylopyranoside ( p NPX). Optimal activity for BsBgl1A was recorded at 45 °C with a pH between 5.6 and 7.6, and 100% of its activity was maintained after a 24 h incubation between pH 4 and 9. Kinetic characterization revealed an enzymatic turnover (Kcat) of 616 ± 2 s −1 (with cellobiose) and 3.5 ± 0.1 s −1 (with p-nitrophenyl-β- d -glucopyranoside). Interestingly, the recombinant enzyme showed cupric ion (Cu 2+ ), sodium dodecyl sulfate (SDS) and alcohol tolerance at 10 mM for Cu 2+ and 10% for both SDS and alcohol. Additionally, BsBgl1A had high tolerance for glucose (Ki = 2095 mM), which is an extremely desirable feature for industrial applications. Following the addition of BsBgl1A (0.05 mg/ml) to a commercial cellulase reaction system, glucose yields from sugarcane bagasse increased 100% after 1 day at 45 °C. This work identifies a Cu 2+ , SDS, alcohol, and glucose tolerant GH1 β-glucosidase with potential applications in the hydrolysis of cellulose for the bioenergy industry.