Characterization of a β-glucosidase from Paenibacillus species and its application for succinic acid production from sugarcane bagasse hydrolysate

- A β-glucosidase from Paenibacillus sp. was cloned.
- The recombinant enzyme BglA was expressed, purified and characterized.
- The engineered E. coli was constructed for succinate production using cellobiose.
- Sugarcane bagasse hydrolysate could be utilized for bio-based chemicals production.

In this study, a β-glucosidase from Paenibacillus sp. M1 was expressed in E. coli BL21(DE3), purified and characterized. The specific activity of purified BglA was 137.64 U·mg−1 protein with optimal temperature and pH of 50 °C and 6.0. Furthermore, BglA shows excellent adaption to various environmental factors such as temperature, pH and metal ions. Engineered E. coli Suc260 was further reconstructed by overexpressing the β-glucosidase for achieving direct cellobiose utilization, which could efficiently utilize the pretreated sugarcane bagasses hydrolysate (SBH) consisting of 25.30 g·L−1 cellobiose, 9.70 g·L−1 glucose, 5.90 g·L−1 arabinose and 7.10 g·L−1 xylose. As a result, 26.50 g·L−1 and 24.30 g·L−1 succinic acid were produced by strain Suc260(pTbglA) from cellobiose and SBH with corresponding yields of 88.30% and 89.20% using dual-phase fermentation, respectively. This study indicated that incomplete enzymatic hydrolysate of SCB will be a potential feedstock for succinic acid production.