Synthesis of octyl-β-d-glucopyranoside catalyzed by Thai rosewood β-glucosidase-displaying Pichia pastoris in an aqueous/organic two-phase system

• Thai rosewood β-glucosidase yeast whole cells were used to synthesize octyl-glu.
• The efficiency of transglycosylation is much higher than reverse hydrolysis.
• Butyl-glu was used as the substrate in transglycosylation reaction.
• 51.1% and 47.5% conversion rates were achieved in 2 ml and 500 ml reaction systems.
• The reuse experiments showed Pp-DCBGL had a good operating stability.

We explored the ability of a Thai rosewood β-glucosidase-displaying P. pastoris whole-cell biocatalyst (Pp-DCBGL) system to synthesize alkyl β-d-glucosides. The primary investigation centered on the synthesis of octyl-β-d-glucopyranoside (octyl-glu, OG). OG could be synthesized through reverse hydrolysis reaction with very low efficiency. Then, OG was synthesized between BG and octanol by a transglycosylation reaction. In a 2-ml reaction system, OG was synthesized with a conversion rate of 51.1% in 3 h when 5 mg/ml BG was utilized as the glucosyl donor under optimized conditions. And, even after being reused four times, the Pp-DCBGL was relatively stable. Additionally, a 500-ml-scale reaction system was conducted in a 2-L stirred reactor with a conversion rate of 47.5% in 1.5 h. Moreover, the conversion rate did not decrease after the whole-cell catalyst was reused two times. In conclusion, Pp-DCBGL has high reaction efficiency and operational stability, which is a powerful biocatalyst available for industrial synthesis.