Heterologous expression and purification of aldehyde dehydrogenase gene from Bacillus halodurans XJU-1.

Background: For its function of catalysing the reaction of aldehyde to acetic acid, ALDH could be applied to antialcoholismic drug development. However, both of the production and activity of natural ALDH are too low to meet the demand.

Objective: To empirically explore whether aldh gene in Bacillus halodurans XJU-1 could be highly expressed in E.coli BL21(DE3) and to investigate the purification of recombinant protein ALDH.

Methods: The aldh gene in Bacillus halodurans XJU-1 was cloned into prokaryotic expression vector pET30b(+), then transformed into E.coli BL21(DE3) to induce expression of ALDH. Immobilized metal ion affinity chromatography (IMAC) was applied in the separation and purification for ALDH proteins.

Results: The recombinant vector for aldh gene was constructed and expressed in BL21(DE3) successfully. The ALDH recombinant protein was purified by ammonium sulfate precipitation and IMAC, and obtained 30.1% of the recovery with a purification factor 8.81.

Conclusions: The value of these findings, as well as wider implications for increasing the yield and the activity of ALDH, is meaningful.