Characterization of a novel sucrose phosphorylase from Paenibacillus elgii and its use in biosynthesis of α-arbutin

In this study, a previously reported SPase known for its effectiveness in synthesizing α-arbutin, was u sed as a probe sequence to identify a novel SPase fromPaenibacillus elgii (PeSP) in the protein database. The sequence similarity betweenPeSP and the probe was 39.71%, indicating a degree of novelty. Subsequently, the gene encodingPeSP was coexpressed with the molecular chaperone pG-Tf2 inEscherichia coli, significantly improvingPeSP ’s solubility. Following this,PeSP was characterized and employed for α-arbutin biosynthesis. The specific activity of co-expressedPeSP reached 169.72 U/mg, exhibited optimal activity at 35 ℃ and pH 7.0, with a half-life of 3.6 h under the condition of 35℃.PeSP demonstrated excellent stability at pH 6.5 –8.5 and sensitivity to high concentrations of metal ions. The kinetic parametersKm andkcat/Km were determined to be 14.50 mM and 9.79  min− 1·mM− 1, respectively.The reaction conditions for α-arbutin biosynthesis using recombinantPeSP were optimized, resulting in a maximum α-arbutin concentration of 52.60 g/L and a HQ conversion rate of 60.9%. The optimal conditions were achieved at 30℃ and pH 7.0 with 200 U/mL ofPeSP, and by combining sucrose and hydroquinone at a molar ratio of 5:1 for a duration of 25  h.
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research