Efficient expression and purification of recombinant glutaminase from Bacillus licheniformis (GlsA) in Escherichia coli

► Rec. glutaminase (GlsA) from Bacillus licheniformis was efficiently expressed in Escherichia coli. ► Microbial glutaminases are enzymes with potential in biotechnological industries. ► Rec. GlsA was 10×His tagged and could be efficiently purified by one-step IMAC. ► Potential application for bioconversion of glutamine to glutamic acid was shown.