Cloning and expression of a lipase gene from Bacillus subtilis FS1403 in Escherichia coli

A moderate heat-resistant lipase gene from Bacillus subtilis FS1403 was cloned. Sequence analysis revealed that the lipase gene encodes a 212-amino-acid protein containing the conserved motif Ala-X-Ser-X-Gly that is present in other Bacillus lipases. Phylogenetic analysis suggested that the B. subtilis FS1403 lipase gene belongs to family I.4 of bacterial lipase genes. The lipase gene was inserted in pET-28a(+) and expressed in Escherichia coli BL21. SDS-PAGE analysis revealed that the recombinant lipase had a molecular weight of approximately 23 kDa, which corresponded to the predicted size (22.8 kDa) of the deduced protein. The lipase activity was the highest at 50°C and at pH 8.0. The enzyme retained over 70% of the maximal activity at temperatures of 40–60°C and pH 6.0–11.0.