Enhanced lignocellulose biomass hydrolysis in a confined space with cellulase-containing liposomes for high-levels succinic acid production.

The production of high-value succinic acid (SA) from waste jatropha fruit shell (JFS) lignocellulose biomass is considered to be an economical and environmentally friendly strategy. Firstly, the cellulase encapsulated in liposomes was used to construct an efficient enzyme-catalyzed microenvironment. Furthermore, the hydrolysis efficiency of JFS was enhanced by simultaneously activating lignocellulose and in-situ saccharification in ionic liquid (IL). Finally, carbonic anhydrase and phosphoenolpyruvate carboxylase were co-expressed in Escherichia coli to produce SA efficiently from JFS hydrolysate. The results indicated that the enzymatic activity could be maintained at 90.5 % and the total reducing sugar yield was as high as 80.2 % in cellulase-containing liposomes at low temperature of 50 °C for 24 h. In addition, 36.1 g/L SA with a yield of 0.92 g/g could be produced by using JFS hydrolysate. Biocompatible IL choline proline enhance the decomposition of lignocellulose through strong hydrogen bonding, electrostatic mismatch and covalent coupling with lignocellulose and liposomes, and liposomes promote in-situ enzymatic hydrolysis of lignocellulose through the high-energy catalytic conformation of enzymes in a confined space. This work demonstrates the green synthesis of high-value SA using JFS hydrolysate as a feedstock, which holds potential for applications in the conversion of waste biomass into chemical products.