Functional expression of Bacillus subtilis xylanase A in an Escherichia coli derived cell-free protein synthesis system and subsequent expression improvement via DNA gel technique

► Signal peptide sequence was mutated to improve in vitro production of xylanase A. ► Detergents were added to further enhance functional expression in cell-free system. ► DNA gel addition greatly improved the in vitro expression from linear DNA template. ► Combined strategy was efficient to improve the in vitro expression of xylanase A.