Optimized soluble expression of a novel endoglucanase from in .

B1213, a novel microbe isolated from a -producing environment, displayed strong cellulolytic activity on agar plates with glucan as the carbon source and had an activity of 674.5 U/mL after culturing with barley. Genome annotation of identificated a single endoglucanase (EG)-encoding gene, designated as . The endoglucanase BpEG01790 shows 98.28% sequence similarity with an endo-β-1,4-glucanase (EC 3.2.1.4) from belonging to glycoside hydrolase family 8 (GH8). The gene has an open reading frame of 1218 bp encoding a 406 amino acid (AA) residue protein (43.0 kDa) with a 40-AA signal peptide. was successfully cloned into pET28a( +) with and without the signal peptide; however, attempts to overexpress this protein in BL21(DE3) cells using this expression system failed. was also cloned into the pCold TF vector. Active BpEG01790 was successfully overexpressed with or without the signal peptide using the pCold TF vector expression system and BL21 (DE3) cells. Overexpression of recombinant BpEG01790 without the signal peptide was higher compared with the construct that included the signal peptide. Optimization of culture conditions improved the enzyme activity by 12.5-fold. This is the first report describing the heterologous soluble overexpression of an EG belonging to GH8 from using TF as a molecular chaperone.