Continuous biocatalytic production of trehalose in a fixed-bed bioreactor using immobilized trehalose synthase from Pseudomonas stutzeri

The integrated approach of biocatalytic conversion coupled with purification using selective enzyme was developed to achieve continuous trehalose production. The activity of trehalose synthase (TS) derived from three different bacteria-Deinococcus radiodurans, Pseudomonas stutzeri, and Thermus thermophillus-immobilized with chitin-binding domain (ChBD-DrTS, ChBD-PsTS, and ChBD-TtTS, respectively) was compared for the production of trehalose from maltose syrup. The trehalose production yield using ChBD-PsTS was 2.4 and 1.7-fold higher than those using ChBD-DrTS and ChBD-TtTS, respectively, after 24 h at 30 degrees C and pH 7.0. In this study, a continuous bioconversion system was developed for trehalose production using ChBD-PsTS in a fixed-bed bioreactor, resulting in an approximate yield of 72%, and a productivity of 4 g/L/h. Additionally, residual maltose was converted into glucose using glucoamylase, and the 37% of bioethanol was produced. The integrated approach demonstrated remarkable biocatalytic performance, biocatalyst reusability, and high production yield.